LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 

RECEIVED    BY  EXCHANGE 


Class 


BIOLOGY 
LIBRARY 


THE  HEARING  OF  PRIMITIVE 
PEOPLES 


AN   EXPERIMENTAL,   STUDY    OF    THE    AUDITORY  ACUITY 
AND  THE  UPPER  LIMIT  OF  HEARING  OF  WHITES, 
INDIANS,  FILIPINOS,  AINU  AND 
AFRICAN  PIGMIES 


BY 

FBANK  G.  BEUNER,  A.B. 

ASSISTANT    DIRECTOR,   DEPARTMENT   OF   CHILD   STUDY    AND    PEDAGOGIC    INVESTIGATION, 
PUBLIC  SCHOOLS,   CHICAGO. 


Submitted  in  partial  Fulfillment  of  the  Requirements  for  the  De- 
gree of  Doctor  of  Philosophy,  in  the  Faculty  of 
Philosophy,  Columbia  Uni- 
rersity. 


Reprinted  From  the  Archives  of  Psychology,  No.  11. 


NEW  YORK 

THE  SCIENCE  PRESS 
19O8 


THE  HEARING  OF  PRIMITIVE 
PEOPLES 


AN   EXPERIMENTAL   STUDY    OF    THE    AUDITORY  ACUITY 
AND  THE  UPPER  LIMIT  OF  HEARING  OF  WHITES, 
INDIANS,  FILIPINOS,  AINU  AND 
AFRICAN  PIGMIES 


BY 

FRANK  G.  BRUNER,  A.B. 

ASSISTANT   DIRECTOR,   DEPARTMENT   OF   CHILD    STUDY   AND    PEDAGOGIC    INVESTIGATION, 
PUBLIC   SCHOOLS,    CHICAGO. 


Submitted  in  partial  Fulfillment  of  the  Requirements  for  the  De- 
gree of  Doctor  of  Philosophy,  in  the  Faculty  of 
Philosophy,  Columbia  Uni- 
versity. 

V 


Reprinted  From  the  Archives  of  Psychology,  No.  11, 


NEW  YORK 

THE  SCIENCE  PRESS 

1908 


"B7 


BIOLOGY 

LIBRARY 

G 


CONTENTS 

CHAPTER  P*GK 

INTBODUCTION 1 

I.    THE  PEOPLES    4 

PART   I 

UPPEB  LIMIT  OF  AUDIBILITY 
II.    HISTOBICAL 

General    11 

Concerning  Primitive  Races   19 

III.  THE  INSTBUMENT  AND  ITS  GBADUATION 

Descriptive    21 

The  Graduation   23 

IV.  DATA  COLLECTED  ON  UPPEB  LIMIT   30 

Indians    35 

Filipinos    41 

Ainu   44 

Pigmies    45 

V.    UPPEB  LIMIT  AS  AFFECTED  BY  AGE  AND  SEX  46 

Summary  and  Conclusion  51 

PART    II 

AUDITOBY  ACUITY 
VI.    HISTOBICAL 

Concerning  Primitive  Peoples    55 

Quantitative  Auditory  Measures    57 

VII.     INSTBUMENT  FOB  MEASUBINQ  AUDITOBY  ACUITY  64 

Instrument  Illustrated    67 

VIII.    GBADUATION  OF  INSTBUMENT   72 

IX.    METHOD  OF  CONDUCTING  TEST   86 

X.    RESULTS  89 

Indians    96 

Filipinos    101 

Ainu   105 

Pigmies    106 

XI.      SUMMABY    AND    CONCLUSION     .  .109 


ill 


THE  HEARING  OF  PRIMITIVE  PEOPLES 

INTRODUCTION 

IN  the  pages  which  follow  are  presented  some  data  relating  to 
the  problem  of  the  hearing  of  primitive  peoples.  The  study  was 
made  in  connection  with  other  experiments  on  the  inferior  races  at 
the  Louisiana  Purchase  Exposition  in  1904.  During  the  period  of 
the  Exposition,  the  writer,  in  the  capacity  of  Assistant  Superin- 
tendent of  the  Sections  of  Anthropometry  and  Psychometry,  under 
the  Division  of  Anthropology,  in  cooperation  with  Dr.  (now  Pro- 
fessor) E.  S.  Woodworth,  who  was  his  immediately  superior  officer, 
was  commissioned  to  make  a  study,  so  far  as  practicable,  of  the  mental 
and  physical  status  of  the  alien  races  stationed  on  the  Exposition 
grounds.  In  the  arrangements  for  the  tests,  the  entire  problem  of 
the  hearing  of  these  people  was  assigned  to  me — the  ways  and 
means  of  testing  their  hearing,  together  with  the  turn  and  scope  the 
particular  study  of  hearing  should  take. 

When  it  came  to  the  question  of  selecting  the  tests  to  be  made, 
there  was  little  of  historical  precedent  to  aid  in  making  a  choice. 
Dr.  Charles  Myers,  in  the  only  extended  report  on  the  hearing  of 
primitive  peoples  extant,  had  examined  three  phases  of  hearing, 
namely:  (1)  The  upper  threshold  of  pitch,  (2)  the  acuity  for  tones 
of  medium  pitch,  and  (3)  the  perception  of  interval.  In  addition  to 
these  three  tests,  a  number  of  others,  which  might  have  brought  out 
interesting  and  instructive  results,  suggested  themselves  to  me. 
These  related  to  space  perception,  tone  memory  and  imagery,  and 
clang  preferences.  The  scope  of  our  work,  however,  was  subject  to 
certain  definite  limitations. 

In  all,  there  were  stationed  at  the  Exposition  in  one  capacity  or 
another,  something  like  one  thousand  individuals  of  various  races, 
whom  it  might  be  possible  to  measure.  There  were  two  of  us  to 
carry  on  the  work.  One  of  two  alternatives,  consequently,  must  be 
pursued,  (a)  to  restrict  the  number  of  measurements  which  should 
be  made  of  each  individual  or  (ft)  to  confine  the  measurements  to  a 
few  representative  individuals  and  races.  We  chose  the  first  in  the 
hope  that  with  relatively  large  groups  some  fairly  definite  informa- 
tion could  be  obtained.  In  consequence  of  this  limitation  of  the 
number  of  measurements,  it  was  thought  advisable  to  confine  the 
number  of  tests  of  hearing  to  three  or  four.  After  some  considera- 


2  THE   HEARING   OF  PRIMITIVE   PEOPLES 

tion  and  advisement,  I  selected  the  three1  which  Dr.  Myers  had  made 
on  the  Papuans. 

So  far  as  practicable  in  these  tests  of  primtive  peoples,  I  hoped 
to  be  able  to  present  my  conclusions  in  such  terms  that  the  data 
might,  if  desired  at  some  subsequent  time,  be  reviewed  and  the 
measurements  compared.  I  have  consequently  attempted  to  express 
my  data  in  definitely  interchangeable  units,  that  is  in  acoustical 
units  which  are  wholly  objective  in  character.  Much  of  the  work 
included  in  this  report,  for  this  reason,  is  wholly  a  matter  of  physics. 
It  concerns  itself  with  the  graduation  of  the  instruments  employed, 
but,  for  purposes  of  a  quantitative  psychology,  this  phase  of  the 
problem  is  none  the  less  important. 

In  this  connection,  I  desire  to  express  my  indebtedness  of  one 
kind  or  another,  to  those  who  have  particularly  assisted  me  in  the 
undertaking  and  completion  of  the  study  herein  reported.  To  Pro- 
fessor Cattell,  first  of  all,  I  am  especially  indebted  for  suggestions 
relating  to  the  problem  as  my  particular  field  of  research  and  for 
many  valuable  and  kindly  hints  and  criticisms  in  the  treatment  of 

1The  instruments  and  methods  with  reference  to  the  first  two  named, 
(1)  the  measure  of  the  upper  threshold  for  hearing  and  (2)  the  determination 
of  the  acuity  for  tones  lying  within  the  range  of  conversational  speech,  will  be 
fully  detailed  in  the  proper  place.  With  reference  to  the  perception  of  interval, 
however,  a  word  is  necessary  in  this  connection. 

The  usual  method  of  testing  the  perception  of  a  musical  interval  is  with 
the  aid  of  tuning  forks.  I  took  to  the  Exposition  two  Konig  tuning  forks, 
differing  from  each  other  by  four  full  vibrations,  the  one  having  a  vibration 
frequency  of  512,  the  other  516.  On  one  of  the  prongs  of  the  fork  of  lower 
pitch  I  placed  a  metallic  rider,  which  it  was  possible  to  slide  up  and  down  and 
which  might  be  fixed  readily  by  means  of  an  ordinary  thumb  screw.  Thus  the 
pitch  of  the  fork  could  be  raised  or  lowered  without  occasioning  any  wearisome 
delays.  It  seemed  impossible,  however,  to  arrange  the  rider  in  such  a  way  as 
not  to  alter  the  character  of  the  tone  which  followed  independently  of  its  purely 
pitch  character.  With  the  rider  attached,  the  two  forks  possessed  marked 
characteristics  of  clang  tint  by  which  they  could  be  distinguished,  wholly  inde- 
pendently of  the  feeling  of  a  pitch  difference.  My  subjects  were  repeatedly 
warned  that  they  should  neglect  the  individual  peeuliarities  in  the  two  tones 
and  render  a  judgment  based  only  on  their  recognition  of  a  difference  of  pitch. 
It  appeared  that  this  even  my  most  intelligent  subjects  were  unable  to  do,  for 
questionings  always  showed  that  the  individual  peculiarity  of  the  tone  of  each 
fork  had  become  fixed  during  the  earlier  moments  of  the  test,  when  the  differ- 
ence in  pitch  would  be  so  marked  as  to  be  easily  observed  by  all  the  subjects. 
Such  a  method  of  conducting  the  experiment  as  that  just  indicated  seems  neces- 
sary with  children  and  intelligent  adults  to  impress  the  object  of  the  test. 

Since,  with  intelligent  white  subjects,  it  seemed  impossible  to  secure  satis- 
factory data,  it  appeared  unreasonable  to  presume  that  anything  could  be  gained 
from  this  test  on  the  primitive  peoples.  This  test,  therefore,  was  abandoned 
altogether  and  the  hearing  tests  confined  to  two,  (1)  simple  acuity  and  (2) 
upper  threshold  of  hearing. 


INTRODUCTION  3 

the  results.  To  Professor  Woodworth,  it  is  impossible  to  express 
the  full  extent  of  my  obligations.  He  performed  large  numbers  of 
the  tests.  He,  chiefly,  was  instrumental  in  making  the  arrangements 
with  the  officials  in  charge  of  the  several  groups  for  having  the 
natives  brought  to  our  laboratories  for  testing.  His  searching 
criticisms,  encouragement  and  interest  at  all  times  during  the  months 
at  the  Exposition,  and  subsequently,  in  the  work  of  graduating  the 
instruments  have  been  an  unfailing  source  of  inspiration.  To  Pro- 
fessor W  J  McGee,  Chief  of  the  Department  of  Anthropology  at 
the  Louisiana  Purchase  Exposition,  I  am  indebted  directly  for  my 
selection  to  carry  on  the  work.  His  encouragement  in  the  work  also 
and  his  assistance  and  cooperation  in  having  the  peoples  brought  to 
the  laboratories  for  measurement  was  of  inestimable  worth.  To  S. 
M.  McCowan,  Superintendent  of  the  Chilocco  Indian  School,  who 
had  charge  of  the  Indian  Ethnological  exhibit  at  the  Exposition, 
I  am  indebted  for  the  privilege  of  measuring  the  Indians  of  the 
School,  and  to  Major  William  Haskell,  U.  S.  A.,  for  the  privilege  of 
measuring  the  Philippine  Constabulary  soldiery.  For  assistance  in 
interpreting  directions  and  otherwise  aiding  the  measurements,  I 
was  under  obligations  to  Mr.  Inagaki,  of  Tokio,  in  connection  with 
the  Ainu,  Reverend  S.  V.  Verner,  in  connection  with  the  Pigmies, 
Dr.  William  Newcomb,  in  connection  with  the  Vancouver  Indians, 
and  to  Mr.  Cushman,  in  connection  with  the  Cocopas.  Finally,  and 
in  a  more  comprehensive  sense,  I  am  indebted  to  all  those  who  offered 
themselves  as  subjects  for  measurements,  the  mention  of  whose 
names  alone  would  require  many  pages.  Though  mentioned  in  this 
general  way  only,  my  feeling  of  thankfulness  to  them  is  no  less 
sincere. 


CHAPTER   I 

THE  PEOPLES 

IN  all,  I  was  able  to  secure  hearing  records,  which  were  more  or 
less  suitable  for  use  in  making  various  deductions  indicating  indi- 
vidual and  racial  differences,  from  about  four  hundred  individuals. 
These  were  distributed  as  follows:  156  Whites;  63  Indians;  137  Fili- 
pinos (Christianized) ;  10  Cocopa  Indians;  7  Ainu  from  the  Island 
of  Hokkaido,  Japan;  7  Indians  from  Vancouver's  Island;  6  so-called 
African  Pigmies;  and  4  Indians  from  the  region  of  Southern 
Patagonia. 

The  Whites.— The  Whites  whom  we  measured  were  those,  for 
the  most  part,  who  strolled  through  our  laboratories  primarily  to 
view  the  exhibits,  but  offered  themselves  as  subjects  for  our  tests, 
willing  victims  to  be  sacrificed,  as  we  chose,  in  the  interest  of  the 
furtherance  of  scientific  truth.  We  examined  altogether  about  100 
of  each  sex  but  many  of  the  records  were  unavailable  for  my  pur- 
poses, either  because  the  subjects  were  too  young  to  be  used  in 
comparative  tests  or,  to  be  sure,  because  they  had  advanced  too  far 
in  years  to  make  data  concerning  their  hearing  of  value  in  com- 
parison with  those  of  younger  individuals  of  other  races.  Many  of 
the  individuals  were  graduates  from  colleges  and  universities,  others 
were  school  teachers.  A  number  of  professional  and  business  men 
and  women  helped  make  up  the  number.  Indeed,  for  the  most 
part  the  group  was  made  up  of  intelligent  people. 

The  Indians.— Except  the  Christianized  Filipinos  and  Whites, 
the  Indians  constituted  the  most  numerous  group  tested.  However, 
it  can  not  be  said  that  the  Indians  measured  formed  a  single  group, 
for  they  were  brought  from  regions  as  widely  separated  as  the 
Vancouver  Islands  and  Patagonia.  They  belonged  to  approximately 
fourteen  different  stocks,  as  may  be  seen  by  the  groupings  below. 

The  greatest  number  of  individuals  belonged  to  the  Algonkian 
stock.  Next  in  order  came  the  Shoshones,  then  the  Sioux,  Pima, 
Iroquoian  in  the  order  given. 

During  the  whole  of  the  Exposition  period  there  were  kept  at  the 
Indian  School  for  purposes  of  exhibition  something  like  77  Indians. 
Of  this  number  we  tested  27  males  and  44  females.  Of  the  males, 
14  were  full-blooded  and  13  mixed-bloods.  Among  the  females,  but 
four  were  of  true  stock.  The  mixed-bloods  were  in  all  cases  partly 

4 


THE   PEOPLES 


STOCK  OK 
FAMILY 

Algonkian 


Shoshones 


Siouan 


TRIBE 

Sac  and  Fox 
Shawnee 
Pottawattomie 
Piegan 
Chippeway 
Kickapoo 
Cheyenne 

Comanche 
Chemehuevi 
Hopi  or  Moki 

Sioux 
Ponca 
Otae 


STOCK  OK 
FAMILY 

Piman 


Iroquoian 


Scattered  Tribes 
belonging  to  as 
many  stocks 


TRIBE 
Pima 
Opata 
Papago 

Oneida 
Cherokee 

Navajo 

Pawnee 

Silitz 

Muskoki 

Payallup 

Kwaguitl 

Cocopa  or  Seri 

Tehuelche 


white— that  is,  partially  American,  Scotch,  French,  German, 
Swedish,  Spanish  or  Irish.  Not  a  single  individual  among  the  In- 
dian group,  so  far  as  we  know,  possessed  a  negro  strain  in  his 
inheritance. 

It  may  well  be  questioned  whether  any  group  of  individuals  so 
heterogeneously  conditioned  as  was  this,  might,  with  propriety,  be 
lumped  and  treated  as  if  representative  or  typical  of  the  race. 
Indeed,  were  we  dealing  with  traits  in  which  tribal  and  stock  dif- 
ferences are  marked,  as  for  example,  anatomical  features,  such  a 
procedure  would  be  wholly  unwarranted.  Sensory  features,  how- 
ever, are  subject  to  a  smaller  range  of  variation.  Moreover,  these 
Indians  from  the  Model  Indian  School  came  largely  from  the  Indian 
schools  at  Haskell,  Chilocco,  Genoa,  Phoenix  and  Ft.  Shaw.  Many 
of  the  boys  and  girls  were  taken  from  their  homes  at  an  early  age 
and  boarded  at  the  Indian  schools  where  they  were  subjected  to 
social  habits,  intellectual  training  and  industrial  occupations  which 
are  common  to  whites.  For  the  most  part,  they  conducted  them- 
selves as  do  the  young  men  and  women  of  our  cities.  So  far  as  their 
attitude  toward  society  is  concerned,  one  could  not  detect  anything 
that  would  point  directly  to  their  immediately  native  origin.  Hear- 
ing tests,  moreover,  look  to  constitutional  differences  rather  than 
anything  that  may  be  directly  influenced  by  a  social  veneer,  hence 
the  culture  to  which  these  boys  and  girls  had  been  subjected,  we 
might  with  reason  aver,  would  affect  their  sensory  reactions  only 
very  remotely. 

The  membership  of  the  Model  Indian  School  was  made  up  of 
individuals  belonging  to  the  first  twenty-two  tribes  named  above, 
excluding  the  Hopi  or  Moki  people  who  were  connected  with  a  con- 
cession on  the  Pike.  Obviously,  the  numbers  are  altogether  too  few 


6  THE   HEARING   OF  PRIMITIVE   PEOPLES 

to  bring  out  tribal  differences.  All  considered,  therefore,  it  seems 
best  to  treat  the  membership  of  the  Indian  School  as  a  single 
cultural  group,  nor  does  it  seem  necessary  to  indicate  with  reference 
to  this  group  such  physical  and  mental  traits  as  mark  off  the  various 
tribes  of  Indians  aligned  under  the  several  stocks  or  families.  Hav- 
ing lived  for  three  or  four  years  directly  under  the  influence  and 
training  of  an  American  civilization,  the  factors  which  might  arise 
from  differences  in  home  life  and  ancestry  are  for  the  most  part 
obliterated. 

The  Filipinos.— The  137  Filipinos  whose  hearing  was  tested  all 
belonged  to  that  branch  of  the  Philippine  soldiery  known  as  the 
Constabulary.  They  constitute  the  local  police  of  the  Islands,  being 
stationed  in  squads  of  eight  in  the  different  villages  and  districts,  to 
preserve  order.  Inasmuch  as  the  Constabulary  is  a  branch  of  the 
local  civil  service  and  the  remuneration  is  considerably  in  excess  of 
that  received  for  other  manual  vocations,  the  better  element  of  the 
citizenship  has  been  attracted  to  its  ranks.  Those  brought  to  St. 
Louis  were  men  in  the  prime  of  life,  none  older  than  thirty-five  years 
or  younger  than  seventeen.  All  had  attended  school  to  a  certain 
extent  at  least.  None  was  found  to  be  illiterate  or  unable  to  write 
his  name,  tribe,  and  place  of  residence  in  the  Islands.  Many  of 
the  men  were  sons  in  well-to-do  families  who  had  attended  the 
Spanish  and  parochial  high  schools  and  colleges  found  in  the 
Philippines.  Rather  indicative  of  the  scholarly  habits  of  many  of 
the  younger  men  was  their  activity  in  acquiring  our  language.  It 
was  not  uncommon  to  observe  groups  of  men  collected  in  some  place 
apart  with  dictionary  and  grammar,  assiduously  studying  English 
grammatical  forms  and  usages. 

In  collecting  the  group  for  representation  at  the  Exposition,  it 
appears  that  the  men  were  drafted  in  squads  of  eight  from  the 
various  Constabulary  regiments  located  in  every  part  of  the  Archi- 
pelago, there  being,  in  fact,  eight  from  the  Moro  population  of  the 
Island  of  Mindanao.  The  tribes  represented  were  the  Tagalog, 
Visayan,  Ilocano,  Bicol,  Macabebe,  Pampanga,  Pangasinan  and 
other  less  well  established  tribes.  It  does  not  appear  that  any  cri- 
teria of  stature,  strength  and  intelligence  were  used  in  selecting  the 
individuals  for  representation.  Two  legs,  two  arms  and  two  eyes 
were  required.  Besides,  it  was  necessary  for  the  recruit  to  under- 
stand enough  Spanish  to  take  the  orders  of  the  line  in  that  tongue. 
Other  than  these,  there  seem  to  have  been  no  prerequisites. 

The  Cocopa  or  Seri  Indians.— The  Cocopa  or  Seri  Indians  tested 
were  all  males.  For  one  reason  or  another,  sickness,  timidity,  in- 
dolence, the  women  of  the  tribe  could  not  be  induced  to  come  to  the 


THE    PEOPLES  7 

laboratories  where  the  measuring  was  being  done.  It  was  chiefly 
through  the  instrumentality  of  Professor  W  J  McGee  that  the  Seri 
Indians  were  brought  to  the  Exposition.1  As  the  result  of  a  careful 
and  painstaking  study  of  the  social  habits,  customs  and  physical 
characteristics  of  this  interesting  group  of  people,  Dr.  McGee  speaks 
in  the  following  words:  " Isolated  to  a  considerable  extent  on 
Tiburon  Island  (in  northwest  Mexico)  these  people  have  successfully 
resisted  the  innovations  of  the  white  man.  To-day  they  still  culti- 
vate aboriginal  crops  by  aboriginal  methods.  They  are  said  to  be  of 
so  low  a  grade  of  culture  that  they  may  be  classed  as  just  entering 
the  stone  age.  Physically,  the  Seri  are  a  gigantic  people,  perhaps 
not  excelled  in  their  physical  proportions  by  any  other  known  tribe. 
Force  of  circumstances  has  made  them  an  agricultural  people  chiefly, 
though  the  Cocopa  are  also  given  to  the  chase."  Their  habitations 
are  extremely  crude  and  primitive.  Coarse  grass,  branches,  leaves 
or  whatever  may  be  most  convenient  are  thrown  upon  a  crude  frame- 
work of  poles  for  a  roof,  while  the  same  sort  of  an  improvised 
material  serves  for  walls.  Such  a  habitation  serves  illy  the  purposes 
of  protection  from  either  heat  or  storm.  The  Seri  Indians  are  not 
as  intelligent  as  the  average  of  the  Indian  race.  They  are  inert, 
unresponsive  to  new  impressions,  dull  and  stupid  in  the  face  of  an 
untried  problem,  and  succumb  readily  to  a  difficult  situation.  With 
the  older  members  of  the  group,  especially,  our  efforts  to  make  them 
approach  our  tests  intelligently  had  been  almost  baffling  were  it 
not  for  the  very  able  assistance  and  encouragement  of  an  intelligent 
native  interpreter,  a  half-blood  woman  who  very  ably  interpreted  our 
directions  to  the  several  subjects,  but  even  with  this,  in  some  cases, 
the  task  seemed  hopeless.  Auditory  acuity  measures,  however,  being 
extremely  simple,  less  difficulty  was  experienced  with  respect  to 
them. 

The  Ainu.— The  Ainu,  four  males  and  three  females  of  whom  we 
tested,  are  a  people  of  more  than  ordinary  ethnological  interest. 
Surrounded  by  peoples  of  yellow  skin,  scant  beard  and  little  body 
hair  with  a  head  covering  of  straight  black  hair,  the  Ainu  are  white 
(when  free  from  dirt)  and  their  bodies  and  faces  so  profusely  grown 
with  a  thick  coat  of  hair  that  they  have  been  popularly  described  as 
the  hairy  Ainu.  The  hair,  too,  is  brown  and  wavy  rather  than 
straight.  They  inhabit  the  Island  of  Hokkaido  or  Yezo  of  the 
Japanese  group.  Little  is  known  of  the  people's  origin  or  ethnie 
relations.  Until  recently  they  had  been  little  disturbed  by  other 
peoples,  even  by  the  Japanese  among  whom  they  dwell.  While 

1  Professor  McGee  made  some  extensive  explorations  in  the  Seri  country, 
which  are  reported  at  length  in  the  Annual  Report  of  the  Smithsonian  Insti- 
tution for  the  year  1895-96  (Part  I.,  pp.  1-285). 


8  THE   HEARING   OF  PRIMITIVE   PEOPLES 

natively  the  Ainu  are  hunters  and  farmers,  those  at  the  Exposition 
had  been  under  the  influence  of  American  missionaries,  chief  of 
whom  is  the  famous  Mr.  Bachelor  whose  influence  with  the  native 
Ainu  has  been  remarkable.  Through  his  influence  it  was  that  the 
people  consented  to  leave  their  native  land  for  the  journey  to  this 
far  off  country.  One  of  the  Ainu  young  men  had  attended  Mr. 
Bachelor's  mission  school,  another  had  been  a  servant  to  another 
missionary.  The  father  of  the  household,  an  old  patriarch,  had  also 
been  converted  to  the  Christian  faith,  but  had  never  quite  sur- 
rendered all  of  his  natw  instincts  and  superstitions.  He  was  a 
farmer  and  bear  hunter  and  still  clung  to  the  superstitions  attaching 
to  the  erection  of  a  bear  head  at  the  door  of  the  dwelling  to  ward 
off  evil  spirits  and  omens. 

The  Ainu  are  short  and  stocky,  sluggish  in  movement,  deliberate 
in  action,  excessively  timid  in  the  face  of  a  novel  situation,  and, 
taken  all  in  all,  very  immature  in  their  mental  conceptions  and 
aptitudes.  However,  they  were  willing  and  patient  in  the  tests  to  a 
degree  to  cast  reproach  upon  many  of  our  white  subjects.  The 
Ainu  were  brought  to  America  by  Professor  Frederick  Starr  of  the 
University  of  Chicago.  We  were  much  indebted  also  to  Mr.  Y. 
Inagaki,  a  Japanese  student,  familiar  with  the  Ainu  language,  who 
interpreted  our  directions  to  the  Ainu  subjects.  In  fact,  in  many 
ways,  Mr.  Inagaki 's  kindly  interest  and  assistance  alone  made  the 
tests  on  these  people  at  all  possible.  Especially  was  this  true  be- 
cause of  their  excessive  timidity. 

Vancouver  Indians. — The  Vancouver  Indians  belonged  to  two 
tribes,  the  Kwaguitl  and  the  Nutken.  There  were  present  at  the 
Exposition,  two  members  of  the  first  named  tribe  and  five  of  the 
latter.  Like  the  Ainu  just  described,  some  of  these  people  were 
interrelated.  At  least  four  of  the  group  of  seven  tested  were  closely 
so,  though  we  were  unable  to  discover  in  all  cases  the  exact  character 
and  extent  of  the  consanguinity.  There  were  Atleo,  an  old  man  of 
perhaps  65  years,  his  two  daughters,  Ellen,  aged  35,  and  Anna,  aged 
30,  or  thereabouts,  and  a  nephew,  Jack  Curley,  aged  28.  From  a  sci- 
entific point  of  view,  of  course,  this  was  unfortunate. 

The  physical  proportions  of  the  Vancouver  Indians  are  rather  less 
than  those  of  the  individual  of  the  Algonkian  stock.  The  Vancouver 
Indian  is  shorter  and  slighter  of  build,  but  on  the  whole,  stronger 
and  more  hardy.  He  is  certainly  more  active  as  well  as  more  alert 
than  the  Algonkian.  In  their  native  haunts,  the  men  are  fisherman, 
often  going  miles  to  sea  in  open  boats  in  the  search  of  whale  and 
seal,  which  are  captured  by  skillful  rowing  and  spearing. 

The  Vancouver  women  are  especially  noted  for  their  beautiful 


THE    PEOPLES  9 

blanketry,  skill  in  weaving  and  dyeing.  Some  of  the  men  also  carve 
skillfully  in  ivory  and  wood.  In  common  with  most  Indian  tribes 
of  the  Northwest,  the  Vancouvers  have  elaborate  ceremonial  rites, 
family  legends  bound  up  with  the  family  totem,  and  certain  fiducial 
customs  and  habits,  which  are  the  sacred  possession  of  the  household 
to  which  they  are  attached.  The  totem  and  fiducial  customs  at- 
tached thereto  pass  down  as  a  family  coat-of-arms,  as  it  were,  by 
which  the  tribe  is  distinguished. 

In  point  of  intelligence,  the  Vancouver  Indians  surpassed  any 
of  the  Indians  we  tested  save  only  those  boys  and  girls  at  the 
Indian  schools  who  had  for  years  been  moulded  by  the  influences  and 
habits  of  whites.  We,  therefore,  found  these  people  easy  to  handle 
and  instruct. 

The  Pigmies.— The  group  of  people  popularly  known  as  the 
Pigmies  whom  we  tested  were  made  up  of  individuals  from  three 
tribes;  three  Batwas,  two  Batsubas  and  one  Cheri  Cheri;  all  were 
males.  Their  ages  were  uncertain.  They  were,  however,  boys, 
almost  if  not  fully  grown,  though  I  think  none  was  older  than  25 
years.  It  is  claimed  that  no  Pigmies  had  before  crossed  the 
Atlantic,  and  naturally  they  were  of  peculiar  interest.  Only  two  or 
three  of  the  natives  had  ever  before  left  Congo  territory.  The 
Pigmies  were  brought  to  the  St.  Louis  Exposition  by  Rev.  S.  V. 
Verner,  a  missionary  who  had  spent  some  years  on  the  African 
coast,  and  had  familiarized  himself  with  the  Pigmy  language  and 
social  customs.  Mr.  Verner  related  that  it  required  some  energetic 
persuasion  to  induce  these  people  to  accompany  him  to  St.  Louis. 
The  Pigmy  tribes  observed  by  Mr.  Verner  in  the  Congo  lived  a 
parasitic  existence,  following  the  large  Kaffir  tribes  and  feasting  on 
their  bounty  or  refuse.  It  is  related  that  companies  of  Pigmies  and 
dogs,  intermingled,  station  themselves  at  reasonable  distances  from 
Kaffir  feasts,  spying  with  envious  eyes  the  feasting  banqueters. 
No  sooner  is  an  unwholesome  piece  of  flesh  cast  aside  by  the  Kaffirs 
than  there  ensues  a  scramble  of  Pigmies  and  dogs  indiscriminately 
for  the  rejected  prize.  Whether  all  Pigmies  stand  so  low  in  the  scale 
of  social  culture  we  are  unable  to  say,  but  it  is  held  to  be  applicable 
to  the  group  which  we  tested. 

In  physical  appearance,  the  Pigmy  presents  no  sign  that  might 
lead  one  to  class  him  as  of  degenerate  stock.  Although  not  exceed- 
ing an  American  boy  of  twelve  years  in  stature,  his  bodily  propor- 
tions are  good.  Still,  he  is  not  robust  nor  capable  of  great  endur- 
ance or  extraordinary  feats  of  strength.  This  inferiority,  however, 
probably  has  its  basis  in  habit,  rather  than  in  any  innate  physical 
incapacity.  Active  in  play  and  frolic,  and  with  a  keen  sense  of 


10  THE   HEARING   OF  PRIMITIVE   PEOPLES 

humor,  the  Pigmy  is  a  thorough  optimist.  He  really  enjoys  life, 
indeed,  takes  everything  with  such  a  degree  of  levity,  that  it  was 
only  with  considerable  effort  that  we  were  enabled  to  have  him 
approach  our  tests  with  anything  like  the  seriousness  they  demanded. 
Withal,  the  Pigmy  is  stupid  and  dense  and  apprehends  meanings 
slowly  and  often  incompletely.  The  hearing  tests  being  very  simple 
in  character,  however,  were  understood  with  a  fair  degree  of  appre- 
hension, and  I  have  reason  to  believe  that  the  data  are  reasonably 
representative  of  the  group  measured. 

The  Patagonians— Tehuelche  Indians.— I  was  successful  in  test- 
ing only  four  men  of  the  group  of  Indians  from  southern  Patagonia ; 
their  ages  being  respectively,  18,  24,  35  and  55  years.  At  home,  the 
individuals  on  exhibition  at  the  Exposition  had  been  employed  as 
herdsmen  on  the  Patagonian  prairies.  They  had  learned  the  use  of 
money  and,  furthermore  the  habit  of  rendering  no  service,  no  matter 
how  trivial,  without  a  money  consideration.  This  necessitated  a 
bribe  of  money  before  any  measurements  were  possible. 

Like  many  other  of  the  Indian  tribes,  the  Tehuelche  are  sullen 
and  uncommunicative.  Their  cultural  habits  are  primitive.  Their 
habitation  is  a  tent  made  of  the  skins  of  the  llama  or  guanaco,  sewed 
together  so  as  to  form  a  considerable  sheet.  This  is  then  stretched 
across  poles,  with  the  edges  spiked  to  the  ground.  Within  this  tent, 
the  family  cooks,  sleeps  and  lounges.  As  there  is  no  vent  for  the 
escape  of  smoke,  and  the  floors  are  never  scoured,  filth  and  grime 
abound  everywhere. 

The  Tehuelche  are  horsemen  and  skilful  in  the  use  of  the  bolo,  a 
triple  thong  loaded  at  the  end  with  stone  weights— which  is  thrown 
great  distances  with  unerring  accuracy.  They  are  a  large  people, 
both  men  and  women  being  tall  and  robustly  built.  With  respect  to 
the  four  individuals  measured  by  us,  no  unusual  difficulty  was  ex- 
perienced in  instructing  them  in  the  ways  of  the  tests,  but  I  question 
whether  in  grade  of  intelligence,  they  did  not  exceed  the  average  of 
•the  Patagonian  Indian. 


PART   I 

THE  UPPER  LIMIT  OF  AUDIBILITY 
CHAPTER   II 

HISTORICAL 

THAT  considerable  individual  differences  exist  amongst  persons 
with  regard  to  the  faintest  tone  that  can  just  be  sensed  is  commonly 
recognized,  but  differences  in  the  range  of  hearing  are  not  so  readily 
apparent.     Helmholtz  first  called  attention  to  the  fact  that  the  chirp  \ 
of  the  cricket  is  sometimes  wholly  inaudible  to  people  whose  hearing  j 
is  otherwise  uneffected— who  have  experienced  absolutely  no  diminu-  / 
tion  in  hearing.     Even  after  the  fact  was  known  that  such  individual 
differences  really  exist,  the  experimental  determination  of  the  range 
of  such  variations  long  awaited  some  device  which  would  produce 
and  accurately  evaluate  the  sonorous  stimuli. 

Experiments  with  visual  sensations  present  no  such  difficulties  as 
are  encountered  by  an  investigator  who  works  with  sound.  Among 
visual  stimuli,  qualitative  characteristics  are  overt.  They  stand  out 
in  such  a  way  as  to  be  little  confused  by  an  individual  with  a 
normally  functioning  visual  organ.  Differences  in  color  such  as 
those  between  red  and  green,  yellow  and  blue,  or,  indeed,  yellow  and 
red,  are  readily  perceived,  and  at  the  same  time  differentiate  certain 
qualitative  effects  to  which  there  is  no  analogue  in  the  field  of  audi- 
tion. When  one  is  affected  with  the  sensation  red,  it  has  been  de- 
termined once  for  all  time,  that  the  stimulus  arises  from  a  disturb- 
ance in  the  ether  amounting  to  approximately  450  billions  of  vibra- 
tions to  the  second,  and  that  the  sensation  blue  corresponds  to  a  dis- 
turbance of  approximately  790  billions.  But,  among  the  higher 
orders  of  pitch,  differences  in  tones  as  great  as  an  octave  are  scarcely 
observed,  even  when  they  follow  each  other  in  immediate  succession. 
Indeed,  among  comparatively  low  pitch  values,  the  perception  of 
tone  differences  is  relatively  uncertain.  In  truth,  pitch  differences 
stand  out  as  variations  in  degree  only,  while  color  differences  naively 
are  differences  in  kind. 

Coming  to  the  question  of  accurate  tone  analysis,  the  physical 
difficulties  are  still  more  involved.  What  the  prism  has  been  able  to 
do  for  the  physicist  in  assisting  him  in  establishing  the  wave-length 

11 


12  TEE   HEARING   OF  PRIMITIVE   PEOPLES 

of  any  ray  of  light  whatsoever,  the  resonators  of  Helmholtz  and 
Konig  do  only  very  unsatisfactorily,  in  helping  to  fix  the  components 
of  any  tonal  compound  or  establishing  the  pitch  of  a  given  unknown 
sound.  The  latter,  indeed,  must  still  be  accomplished  by  compli- 
cated registering  devices.  Again,  the  nature  of  auditory  stimuli  is 
such  as  to  make  every  unfamiliar  tone  in  nature  an  almost  wholly 
unknown  quantity,  which  it  becomes  necessary  to  establish,  empiri- 
cally, always  anew.  And  with  a  shrill  tone,  the  empirical  method 
alone  suffices  to  fix  the  pitch  even  roughly. 

Unfortunately,  the  importance  of  knowing  the  exact  character  of 
the  stimuli  employed  has  not  always  been  appreciated  by  investi- 
gators in  the  field  of  hearing.  Especially  is  this  to  be  regretted  in 
the  reports  of  investigations  on  the  limits  or  the  range  of  audition. 
It  thus  happens  that  on  account  of  a  diversity  of  statement  and 
lack  of  precision  in  the  definition  of  the  tones  employed,  it  is  wholly 
impossible  to  compare  the  data  of  different  investigators.  But  they 
serve  to  emphasize  the  futility  of  any  research  in  the  field  of  hearing 
unless  the  physics  of  the  problem  involved  has  first  been  clearly 
worked  out.  Some  figures  relating  to  the  upper  threshold  of  hear- 
ing, given  out  by  different  investigators,  will  serve  to  illustrate  what 
I  have  just  indicated. 

Blake  and  Appunn1  who  are  among  the  foremost  investigators  of 
the  upper  limit  of  audibility,  think  the  human  ear  to  be  sensative  to 
tones  of  50,000  or  60,000  double  vibrations  to  the  second.  Preyer2 
placed  the  extreme  upper  limit  at  40,000  vibrations;  Konig,3  with 
the  use  of  short  sounding  rods  and  a  modification  of  the  Galton 
whistle,  got  results  substantially  in  agreement  with  those  of  Preyer. 
With  a  Galton  whistle  blown  by  a  constant  air  blast,  Zwaardemaker4 
believed  he  could  produce  audible  tones  whose  vibration  rate  ex- 
ceeded  33,000  to  the  second.  But  all  these  data  were  called  in 
question  by  Melde,5  who  pointed  out  that  previous  investigations 
were  valueless  because  of  instrumental  errors.  Melde 's  objective  ex- 
periments with  different  makes  of  instruments  led  him  to  believe  that 
no  ear  is  sensitive  to  tones  above  24,000  double  vibrations  to  the 
second.  Melde 's  investigations  were  repeated  and  elaborated  by 
Schwendt,6  who  reached  the  conclusion  that  with  the  Galton  whistle, 

1  Annal.  d.  Phys.  u.  Chem.  64:  409.    1898. 

2 "Die  Grenzen  der  Tonwahrnehmung "  (English  trans.),  Proc.  Mus.  Assn., 
1876,  pp.  1-32. 

9  Annal.  d.  Phys.  u.  Chem.  69:  626-66,  721-38.    1899. 

*  Arch.  f.  Ohrenhk.  35:  30.    1893;  Ztschr.  f.  Psychol.  7:  10.    1894. 

•Pfluger's  Arch.  71:  441.  1898;  Annal.  d.  Phys.  u.  Chem.  67:  781-793. 
1899. 

'Pfliiger's  Arch.  75:  346-64;  76:   189-91.    1899. 


UPPER    LIMIT    OF    AUDIBILITY— HISTORICAL  13 

audible  tones  of  greater  vibration  frequency  than  22,000  can  not  be 
produced.  However,  with  an  instrument  modeled  after  the  type  of 
the  steam  whistle  (Edelmann's),  Schwendt7  found  that  where 
greater  intensities  of  air  blasts  might  be  employed,  a  tone  of  the 
value  of  49,000  double  vibrations  might  still  be  heard.  With  the 
same  whistle,  Edelmann8  put  the  upper  limit  at  50,000  double  vibra- 
tions. By  a  singular  method  Stumpf  and  Meyer,9  in  which  some 
Konig  forks  and  an  Appunn  Galton  whistle  were  graduated  by  a 
method  of  difference  tones,  believed  a  greater  vibration  rate  than 
20,000  inaudible.  Still  more  recently,  after  some  extended  objective 
experimentation  with  a  Galton  whistle  of  the  Hawksley  pattern,  Dr. 
Charles  Myers10  concluded,  at  least  so  far  as  the  Hawksley  whistle 
goes,  that  tones  above  24,000  double  vibrations  to  the  second  can  not 
be  made  of  such  an  intensity  as  to  be  audible,  nor  indeed  measured 
by  any  known  means. 

It  is  scarcely  necessary  to  enter  into  a  detailed  discussion  of  the 
factors  responsible  for  such  wide  discrepancies  in  results  as  these 
shown  between  instrument  makers  on  the  one  hand  and  scientific 
investigators  on  the  other.  A  review  of  the  literature  relating  to  this 
work,  notwithstanding,  forces  the  conviction,  that  the  variations 
are  due  to  instrumental  differences  almost  wholly— being  complicated 
by  the  failure  to  allow  for  the  physical  and  physiological  factors 
involved  in  the  tests  conducted.  Much  of  the  early  work  suffers 
from  inefficient  methods  of  arriving  at  the  vibration  frequencies  of 
the  tones  that  have  been  employed  in  making  the  physiological  meas- 
urements. A  great  deal  of  the  later  work  on  the  upper  limit  of  hear- 
ing is  of  the  same  character.  If  we  add  to  this  difficulty  the  fact 
that  the  physiological  value  of  tones  for  the  ear  has  been  ignored, 
it  is  not  improbable  that  most  of  the  differences  would  be  accounted 
for.  In  keeping  with  this  conviction  are  the  recent  investigations  of 
Wien  and  Zwaardemaker. 

Wien11  and  Zwaardemaker  and  Quix12  have  shown  that  the  ear  is 
most  sensitive  to  tones  whose  pitches  are  of  the  middle  values,  those 
lying  roughly  within  the  range  covered  by  conversational  speech 
(400  D.  V.  to  4000  D.  V.).  Both  above  and  below  these  values, 
the  ear's  sensitivity  is  found  to  diminish  rapidly.  Indeed,  as  early 

1Verhandl.  d.  Naturforsch.  Gesellsch.,  Basel,  12:  (1900) ;  Arch.  f.  Ohrenhk. 
48:  1.  1900. 

*Annal.  d.  Phys.  2:  469.    1900;  Ztschr.  f.  Ohrenhk.  36:  330.    1900. 

'Annal.  d.  Phys.  u.  Chem.  N.  F.  61:  760-79.    1897. 

10  "The  Pitch  of  Galton  Whistles,"  J.  of  Physiol.  23:  417.    1902. 

"Pfliiger's  Arch.  97:   1.    1903. 

"Arch.  f.  (Anat.  u.)  Physiol.  (Suppl.) ,  1902,  367-98;  also  Ztschr.  f. 
Psychol.,  u.  s.  w.  33:  407.  1904. 


14  THE   HEARING   OF  PRIMITIVE   PEOPLES 

as  1878,  Helmholtz  (Tonempfindungen)  pointed  out  that  the  ear's 
range  of  sensitivity  could  not  be  safely  divorced  from  the  factor  of 
the  intensity  of  the  tonal  elements,  but  the  importance  of  this  fact, 
as  related  to  the  upper  and  lower  thresholds  of  audition,  has  until 
recently  received  little  thought.  Scripture  and  Smith13  in  review- 
ing the  factors  involved  in  the  wide  variations  discovered  by  those 
who  have  investigated  the  ear's  range  of  sensibility  again  called 
attention  to  the  importance  of  the  intensity  factor  and  suggested 
that  perhaps  the  differences  in  recorded  experimental  results  might 
be  explained  on  this  basis.  Some  experiments  with  the  Galton 
whistle,  in  which  various  degrees  of  wind  pressure  were  employed 
convinced  them  that  if  the  intensity  of  the  stimuli  could  be  made 
sufficiently  great,  the  ear  would  be  found  to  be  sensitive  to  tones 
whose  vibration  frequency  exceeded  50,000  or  even  55,000  D.  V.  It 
must  be  confessed,  however,  that  their  empirical  evidence  for  such 
a  conclusion  is  not  particularly  convincing. 

In  the  light  of  recent  experimental  results,  it  would  not  be  over- 
confident to  believe  that  such  wide  discrepancies  as  the  figures  from 
different  observers  show  would  largely  disappear  were  it  possible  to 
reckon  and  allow  for  the  two  factors  just  indicated— the  physical, 
concerned  with  graduation  and  intensity,  and  the  physiological,  con- 
cerned with  the  ear's  relative  sensitivity.  Both  of  these  factors  are 
so  interrelated  in  the  historical  data  to  be  considered,  that  it  is  im- 
practical to  attempt  to  separate  them.14  This  condition  comes  about 
partially  at  least  because  no  uniform  type  of  instrument  has  been 
employed  for  measuring  the  upper  threshold  of  hearing.  Appunn,15 
Preyer/6  and  Koenig17  used  small  tuning  forks  in  which  the  instru- 
ments themselves  possess  certain  physical  limitations  confining  the 
possible  intensities  of  the  tones  to  very  narrow  limits.  Koenig 's 
"rods"  possess  the  same  deficiency.  It  appears  that  all  of  these  in- 
struments uniformly  were  assigned  tonal  values  altogether  too  high. 

13  See  "  Highest  Audible  Tones,"  Studies  from  the  Psychological  Laboratory 
of  Tale  University,  1894,  p.  105. 

14  To  Schwendt  particularly  do  we  owe  a  method  for  evaluating  the  vibra- 
tion frequencies  of  tones,  which  is  wholly  independent  of  the  experimenter's 
auditory   sensitivity.     As    Schwendt   remarks,    it   is    a   method   that   may   be 
employed  equally  well  by  a  person  wholly  devoid  of  hearing,  and  consequently 
eliminates  so  far  as  such  a  thing  is  possible,  the  element  of  the  personal  equa- 
tion.   The  method  consists  of  an  adaptation  of  the  Kundt  dust  figures  to  tubes 
of  small  bore  and  sound  waves  of  extremely  small  extension.     See  Annal.  d. 
Phys.  u.  Chem.  N.  F.  61:  760-69.    1897. 

a  Annal.  d.  Physik  u.  Chem.  64:  409.    1898. 

"Pfliiger's  Arch.  71:  441.  1898;  Wiedemann's  Annal.  51:  683.  1894;  52: 
238.  1894. 

1T  Pfluger*8  Arch.  75:  346.    1899. 


UPPER    LIMIT    OF    AUDIBILITY— HISTORICAL  15 

Melde,16  who  put  to  experimental  test  the  pitch  values  assigned  to  the 
tuning  forks  used  in  Preyer  and  Appunn  'a  experiments,  entirely  dis- 
credited them.  His  results  were  later  confirmed  by  Schwendt.17 
The  Appunn  fork  marked  (g8)  50,000  (double  vibrations)  was 
found  to  have  a  vibration  rate  of  only  13,157  D.  V.  The  pitches  of 
the  remaining  forks  of  the  series  were  overstated  to  about  the  same 
degree. 

What  has  just  been  said  of  the  tuning  forks  applied  with  equal 
force  to  the  sounding  rods  of  Konig.  His  highest  pitched  rod,  ac- 
cording to  the  optographic  measurements  of  Melde,  gave  a  tone  of 
(f7)  21,845  D.  V.,  although  Konig  had  assigned  to  the  same  rod  a 
value  of  40,000  D.  V.  Much  of  the  error,  no  doubt,  arose  on  account 
of  the  method  used  for  assigning  the  pitch  values  to  the  different 
forks  and  rods.  Preyer,  Konig  and  Appunn  believed  that  forks 
could  be  graduated  with  sufficient  accuracy  for  ordinary  scientific 
purposes,  with  the  unaided  ear.  According  to  Preyer,18  practised 
musicians  can  distinguish  with  certainty  a  difference  in  pitch 
amounting  to  one-half  a  vibration  between  the  limits  of  "C"  and 
* '  c2. "  Were  it  possible  for  practised  observers  to  discriminate  tonal 
differences  as  accurately  for  all  parts  of  the  hearing  scale,  the  gradu- 
ation of  instruments  for  measuring  the  upper  limit  of  hearing  might 
well  be  made  by  some  such  subjective  method  as  these  investigators 
employed.  But  the  perception  of  interval  is  extremely  deficient  for 
tones  above  "c3,"  as  the  experiments  of  Konig19  with  sounding  rods 
and  those  of  Preyer19  with  tuning  forks  have  pointed  out.  With 
tones  in  the  sixth  octave  an  interval  of  a  fifth  is  scarcely  observable, 
while  for  tones  in  the  seventh  octave  and  above  an  interval  of  an 
octave  passes  unnoticed  even  by  musical  ears.  As  Schwendt  has 
well  remarked,  it  is  not  improbable  that  the  production  of  audible 
tones  of  a  pitch  exceeding  25,000  vibrations  to  the  second,  with  a 
tuning  fork  or  rod  is  a  physical  impossibility  owing  to  the  extreme 
weakness  of  tones  coming  from  such  sources.  Where  the  forks  are 
made  as  small  as  those  must  be  to  give  a  tone  above  25,000,  the 
energy  given  out  is  much  diminished.  Schwendt  further  pointed 
out  that,  even  were  their  production  possible,  no  known  means  exists 
for  determining  the  vibration  rate.  The  methods  in  use  for  de- 
termining the  vibration  frequencies  of  tones  are  wholly  inapplicable 
to  tones  of  so  small  energy  value  as  these.  Indeed,  Schwendt  found 
the  resonance  method  inapplicable  for  the  forks  and  rods  of  a  vibra- 
tion frequency  exceeding  15,000. 

18 "On  the  Limits  of  the  Perception  of  Tone"    (trans.),  Proc.   Musical 
Assn.  1896-7,  pp.  1-32. 

19  Helmholtz,  "  Tonempfindungen  "  (4th  ed.),  p.  147. 


IQ  THE   HEARING   OF  PRIMITIVE   PEOPLES 

By  far  the  most  common  device  for  measuring  the  upper  limit  of 
hearing  has  been  some  form  of  the  Galton  Whistle.  This  type  of 
threshold-whistle,20  devised  by  Sir  Francis  Galton,  is  constructed  on 
the  model  of  the  closed  organ  pipe,  with  vibrating  lip  and  resonance 
cavity.  In  a  closed  organ  pipe,  Helmholtz  and  also  Lord  Rayleigh21 
found  that  theoretically,  at  least,  the  vibration  frequency  is  a  definite 
function  of  the  length  of  the  resonance  cavity.  Knowing  the 
velocity  of  sound  in  air  at  the  temperature  prevailing  "Va"  the 
length  of  the  resonance  cavity  "L,"  the  vibration  frequency  "N"  in 
double  vibrations  may  be  computed  directly  from  the  formula 

*-£. 

4L 

In  point  of  fact  this  theoretical  formula  is  not  wholly  valid 
even  for  closed  pipes  of  relatively  large  dimensions  as  has  been 
experimentally  demonstrated  by  Savart,22  Liscovius  and  Wertheim23 
and  others  and,  indeed,  the  formula  has  been  shown  to  be  wholly 
inapplicable  to  pipes  of  small  bore.24  Differences  in  the  pressure 
of  air  blast  employed,  the  ratio  between  the  length  and  width  of  the 
resonance  cavity,  the  dimensions  and  shape  of  the  mouth  slit,  together 
with  the  materials  of  which  the  whistles  are  made,  all  have  been 
proven  to  be  extremely  important  factors  in  determining  the  pitch 
of  Galton  whistles  as  well  as  all  other  closed  pipes  of  this  variety. 

As  the  diameter  of  the  resonance  cavity  increases,  the  tone 
deepens  but,  on  the  other  hand,  the  pitch  becomes  more  acute  as 
the  wind  pressure  becomes  greater.  Such  considerations  make  im- 
possible any  mathematical  formula  generally  applicable  to  threshold 
pipes.  It  has  been  found,  moreover,  that  no  matter  how  painstaking 
and  skilful  the  construction  in  the  attempt  to  duplicate  a  threshold 
whistle  differences  are  certain  to  result,  which  make  it  necessary  to 
graduate  objectively  each  whistle  independently. 

In  the  experiments  of  Stump f  and  M.  Meyer,25  in  which  Galton 
whistles  were  used,  the  graduations  were  also  made  subjectively. 
These  investigators  depended  on  the  observation  of  difference  tones. 
By  blowing  two  whistles,  whose  pitches  differed  by  about  2000 
double  vibrations  to  the  second,  simultaneously,  a  difference  tone 
resulted  whose  pitch  these  investigators  believed  they  could  place 

"This  whistle  is  described  in  Galton's  "Inquiries  into  Human  Faculty," 
p.  38. 

nPhil.  Mag.  22:   344.    1879. 

22  Wiillner's  "  Experimental  Physik,"  Bd.  2,  p.  324. 

28  Op.  tit.  Bd.  1,  p.  886. 

"Vid.  Myers,  J.  of  Physiol.  28:  417.    1902. 

"Annal.  d.  Phys.  u.  Chem.  61:  760-79.    1897. 


UPPER    LIMIT    OF    AUDIBILITY— HISTORICAL  17 

accurately  by  ear.  Then,  by  increasing  the  pitch  of  each  whistle 
alternately,  graduations  were  made  until  the  point  was  reached 
where  the  tones  faded  entirely.  A  similar  method  was  pursued  with 
the  Konig  tuning  forks  and  the  sounding  rods. 

Certain  serious  criticisms,  however,  have  been  offered  against  the 
method.  In  the  first  place,  difference  tones  are  difficult  to  recog- 
nize at  all  times  and  one  is  never  quite  certain  whether  the  difference 
tone  is  the  difference  between  the  vibration  frequencies  of  the 
fundamentals  of  the  two  tones  employed  or  of  their  octaves,  or,  per- 
haps, of  the  second  upper  partials.  It  depends  altogether  upon 
the  relative  intensities  of  the  various  components,  factors  indeed,  of 
which  we  are  never  quite  certain  in  the  production  of  very  acute 
tones.  Helmholtz26  observes  that  while  the  method  of  difference 
tones  is  possible  with  pitches  whose  vibration  frequencies  fall  below 
10,000,  for  values  higher  than  this  the  method  is  extremely  uncer- 
tain. In  point  of  fact  when  Stumpf  and  Meyer's  graduations  were 
put  to  experimental  test  they  were  shown  to  be  not  at  all  reliable. 
Employing  a  resonance  method  for  evaluating  the  pitches  of  the 
instruments  used  by  these  investigators,  Melde27  found  that  the 
graduations  were  not  accurate  to  within  10,000  double  vibrations  for 
the  shriller  tones— those  of  f7  and  above. 

There  has  been  on  the  market,  during  recent  years,  an  improved 
form  of  threshold  whistle  devised  by  T.  L.  Edelmann.28  It  is 
asserted  that  this  instrument  overcomes  the  objections  put  against 
the  older  Galton  form.  Edelmann  believes  that  with  his  whistle 
tones  of  110,000  D.  V.  can  easily  be  produced  and  the  vibration  fre- 
quencies fixed;  tones,  to  be  sure,  which  are  far  too  high  for  any  ear 
to  sense.  The  mechanism  of  the  whistle  is  such  as  to  consume  con- 
siderably more  energy  in  its  operation  than  the  ordinary  Galton 
type  and  it  likewise  gives  out  a  tone  whose  intensity  is  many  times 
in  excess  of  that  given  out  by  the  Galton  whistle.  Zwaardemaker 
and  Quix29  discovered  that  the  upper  threshold  of  hearing  might 
be  raised  a  major  third  by  increasing  the  intensity  of  the  tone  1,000 
times,  and  Wien  thinks  that  it  may  be  raised  at  least  a  full  octave 
if  the  intensity  can  be  increased  10,000  times.30 

28  "  Tonempfindungen  "   (4th  ed.),  p.  203. 

a  Uber  die  verschiedenen  Methoden  der  Bestimmung  der  Schwingungs- 
zahlen  sehr  hohen  Tone,  Annal.  d.  Phys.  u.  Chem.  67:  781-93.  1899. 

29  This   whistle,   together   with   the   methods   for   its   graduation,    is    fully 
described  by  the  inventor  in  an  article  in  Annal.  d.  Physik  (N.  S.)  4:  469-82. 
1900. 

"Ztschr.  f.  Psychol.,  u.  s.  w.,  33:  407.    1904. 
"Pfluger's  Arch.  97:  1.    1903. 


18 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


These  conclusions  confirm  the  conviction  of  Scripture  and  Smith, 
referred  to  above.61  Exactly  in  the  same  direction  point  some  of 
the  experiments  of  Dr.  Chas.  Myers,  in  which  an  Edelmann  whistle 
with  different  degrees  of  wind  blast  was  used.  His  statement  of 
the  facts  is  so  convincing  that  I  quote  his  own  words:  "When  the 
wind  pressure  was  30-35  mm.  of  water,  a  very  faint  quivering  note 
was  heard.  The  note  rose  gradually  until  a  wind  pressure  of  140 
mm.  of  water  was  reached  when  the  tone  disappeared.  Increasing 
the  pressure  100  mm.  the  tone  was  again  audible,  and,  at  a  wind 
pressure  of  800  mm.  of  water,  the  tone  was  at  least  an  octave 
higher."  With  a  pipe  length  of  1.3  mm.  and  mouth  width  of  0.75 
mm.,  employing  the  Schwendt  dust  figures  for  evaluating  the  pitch 
numbers,  Meyers  got  the  following  significant  figures:  When  the 
wind  blast,  measured  by  water  pressure  was  36  mm.,  the  vibration 
frequency  was  5,673. 

With  a  water  pressure  of  109  mm.  the  vibration  frequency  was  10,942 
With  a  water  pressure  of  680  mm.  the  vibration  frequency  was  23,315 
With  a  water  pressure  of  800  mm.  the  vibration  frequency  was  28,332 

The  last  figure  exactly  corresponds  to  that  given,  for  the  same  ad- 
justments, in  the  chart  which  the  makers  sent  with  the  Edelmann 
whistle  used  in  the  experiments  to  be  detailed  in  this  writing.  This 
tone  and  many  much  higher  were  easily  heard  not  only  by  myself, 
but  also  by  a  majority  of  my  adult  subjects.  There  is  no  question 
but  that  the  fundamental  objection  to  the  Galton  whistle  used  by 
Zwaardemaker,  Stumpf,  Dr.  Chas.  Myers  and  others,  as  well  as  to 
the  tuning  forks  and  sounding  rods,  lies  in  this,  that  the  tones  pro- 
duced are  too  feeble,  not  only  to  cause  a  disturbance  of  the 
lycopodium  powder  in  the  dust  tubes,  but  also  to  reach  the  physio- 
logical threshold  of  the  auditory  end  organs  for  tones  of  the  upper 
pitches. 

So  much  for  the  literature  referring  specifically  to  the  physics 
and  physiological  factors  of  the  problem.  Now,  let  us  look  for  such 
sensory  differences  as  have  been  discovered. 

In  the  light  of  the  sources  of  error  mentioned  above,  the  sensory 
data  thus  far  collected  are  almost  hopelessly  bemuddled. 

Zwaardemaker,32  perhaps,  has  collected  more  data  of  individual 
and  age  differences  as  regards  the  upper  limit  of  hearing  than  any 
one  else,  but  his  results  are  not  even  comparable  among  themselves. 
In  some  of  his  experiments,  a  form  of  the  Galton  whistle  was  em- 
ployed, graduated  by  the  Stumpf-Meyer  method.  In  still  other  of 

*Loc.  tit.,  p.  108. 

"Annal.  d.  Phys.  u.  Chem.   (N.  F.)   61:  760-79.    1897. 


UPPER    LIMIT    OF    AUDIBILITY— HISTORICAL  19 

his  experiments,  the  pitch  values  of  the  different  whistle  lengths 
were  fixed  by  comparing  the  tones  given  out  with  those  of  the 
Konig  rods  or  the  Konig  tuning  forks.  The  untrustworthiness  of 
both  of  these  methods  of  making  graduations  has  been  pointed  out 
above.  Zwaardemaker's  "e8,"  a  tone  which  many  of  his  subjects 
heard  distinctly  was  found'33  to  be  wholly  fictitious. 

Regarding  the  upper  limit  of  hearing  of  whites,  the  literature  is 
not  at  all  scant.  But  even  were  it  possible  to  separate  out  the 
data  in  which  the  instrumental  defects  have  been  least  prominent, 
it  would  still  be  difficult  to  draw  comparisons.  Without  exception, 
the  distrbution  of  cases  has  been  omitted  in  the  data  presented. 
Most  of  the  work  on  the  upper  range  of  hearing  has  been  carried  on 
for  the  purpose  of  determining  age  differences.  It  has  been  pretty 
well  established  that  the  upper  limit  of  hearing  contracts  with 
increasing  years  of  life.  Zwaardemaker,34  Cuperius,34  Alderton,35 
Myers,36  and  others  have  contributed  rather  convincing  data  on 
this  phase  of  the  problem. 

The  results  obtained  are  so  significant  as  to  justify  the  inclusion 
of  tables  summarizing  them: 

Zwawrdemaker"  Cuperius3"1 

Ages  Whistle  Length  Pitch  Whistle  Length  Pitch 

Under  10  yrs.  1.22  mm.               e7 

10-20    "  1.39    "  disT  1.08  mm.  f 

20-30    "  1.39    "                  "  1.19    "  e7 

30-40    "  1.58    "                   "  1.31    " 

40-50    "  2.23    "  cis1  1.39    "  disT 

50-60    "  2.93    "                   h"  2.08    "  cis7 

Over     60    "  3.03    "  cis6  3.02    "  cis8 

Alderton  reports  as  follows  the  examination  of  500  individuals 
with  the  Gatonj  whistle: 

For  children  up  to  12  years — pipe  length  on  the  average  . .   1.24  mm. 
For  adults — pipe  length  on  the  average   3.03  mm. 

Dr.  Charles  Myers's36  tests  of  Scotch  children  point  in  the  same 
direction. 

The  Upper  Limit  of  Audibility  among  Primitive  Races.— Bo  far 
as  I  have  been  able  to  discover,  no  measurements  of  this  character 
save  those  of  Myers  and  my  own  herein  reported,  have  ever  been 

33  Myers,  op.  tit. 

"Arch.  f.  Ohrenhk.  33:  54.    1893;  Ztschr.  f.  Psychol.  7:   11.    1894. 
35 Arch,  of  Otology,  23:  71.    1894;  25:  43.    1896. 

86  Report  of  the  Cambridge  Anthropological  Expedition  to  Torres  Straits, 
Vol.  2.  1903. 

"Ztschr.  f.  Psychol.  7:   10.    1894. 


20 


THE   HEARING   OF  PRIMITIVE    PEOPLES 


made.  In  their  work  on  the  upper  limit  of  hearing  of  the  native 
Papuans  of  the  Murray  Islands,  Rivers  and  Myers38  used  the 
Hawksley  pattern  of  the  Galton  whistle.  This  was  an  instrument 
with  an  extremely  small  bore,  such  as  to  make  it  possible  to  produce 
very  high  pitched  tones.  Dr.  Myers,  who  reports  the  hearing  tests, 
was  inclined  to  put  little  faith  in  the  graduations  of  his  instrument, 
a  task  which  was  performed  after  he  had  returned  to  England,  so 
the  data  relative  to  sensory  differences  are  given  in  terms  of  the 
length  of  the  cavity  of  the  whistle.38  His  results  are  presented  so 
as  to  show  at  the  same  time  race  and  age  differences.  I  summarize 
them  in  the  following  table: 

Murray  Islanders  Aberdeenshire  Folk 

Whistle  Whistle 

No.  Age  Length  No.  Age  Length 

Children    2  5-9  yrs.  2.25  mm.  Children    4         5-9  yrs.  1.97  mm. 

15  10-15  "  2.07  "                                18       10-15    "  1.99  " 

Adults        5  16-19  "  2.25  "  Adults       

9  20-29  "  3.00  "                                         20-29    "  2.22  " 

12  30-39  "  3.17  "                                          30-39    "  2.63  " 

9  40-49  "  3.53  "                                         40-49    "  3.19  " 

10  Over  50  "  4.68  "                                      Over  50    "  3.77  " 

It  appears  from  this  table  that  for  all  ages  the  upper  threshold 
of  hearing  of  the  Papuans  is  lower  than  for  Scottish  people  of  cor- 
responding years.  It  is  a  conclusion  that  is  significant,  notwith- 
standing that  the  numbers  tested  for  the  several  ages  were  small. 
More  of  this,  however,  in  connection  with  the  discussion  of  my  own 
figures. 

88  Dr.  Myers  employed  a  number  of  methods  in  making  the  graduations  of 
tonal  values  corresponding  to  the  different  cavity  lengths  in  the  tests.  Chief 
of  these  are  the  resonance  method  and  optographic  method.  See  J.  of  Physiol. 
24:  417.  1902. 


CHAPTER   III 

THE  INSTRUMENT  AND  ITS  GRADUATION 

I  EMPLOYED,  for  measuring  the  upper  range  of  audibility,  the 
Edelmann  modification  of  the  Galton  whistle.     It  is  probably  too 
commonly   known   to    require    description.1     It    differs  from    the 
familiar  Galton  form,  in  being  modeled  after  the  pattern  of  the 
steam  whistle  instead  of  the  closed  organ  pipe.     In  the  opinion  of 
Edelmann,  this  improved  pattern  possesses  some  marked  advantages 
over  the  old  form.     In  the  first  place,  the  different  parts  are  con- 
structed separately,   allowing  of  finer  work.     The  whistle  cavity 
itself  is  a  perfect  cylinder,  which  makes  it  possible  to  turn  it  out 
very  delicately  on  a  lathe.     Then,  the  whistle  possesses  a  means 
whereby  the  width  of  the  lip  opening  may  be  varied,  so  as  to  allow 
for  the  large  quantity  of  air  that  must  pass  through  it  in  producing 
low  pitched  tones,  and  still  avoid  the  air  puff  with  extremely  shrill 
tones.     In  measurements  with  the  Galton  whistle  this  air  puff,  which 
accompanies  very  high  tones,  is  extremely  confusing  especially  to 
untrained  subjects.    Not  infrequently  a  subject  states  that  he  is  not 
certain  whether  he  hears  a  tone  or  wind  only.    Dr.  Myers2  observes 
in  connection  with  his  work  on  the  native  Papuans  in  which  the 
older  Galton  type  of  instrument  was  employed,  that  there  was  con- 
stant confusion  between  the  perception  of  the  sound  and  that  of  the 
air  puff,  which  always  accompanied  it.    While  I  do  not  think  that 
this  difficulty  is  entirely  obviated  by  making  the  mouth  width  of  the 
whistle  adjustable,  as  in  the  Edelmann  pattern,  yet  there  is  no  ques- 
tion but  that  the  Edelmann  whistle  is  superior  in  this  respect  to  the 
old  Galton  form.     In  my  own  experiments,  I  had  never  observed 
that  any  subject  found  difficulty  in  distinguishing  between  the  ac- 
companying air  puff  and  the  tone  and,  indeed,  when  the  whistle  was 
so  far  as  25  centimeters  from  the  ear,  almost  no  air  puff  was  ever 
audible. 

1  Those  not  familiar  with  the  instrument,  I  refer  to  the  inventor's  (Pro- 
fessor Edelmann's)  able  description  and  careful  drawings  to  be  found  in  the 
Annalen  der  Physik  for  1900.  4  Folge,  Bd.  2,  S.  469.  Those  also  unfamiliar 
with  the  Galton  whistle  may  find  a  description  of  this  instrument  in  Galton's 
"Inquiries  into  the  Human  Faculty,"  1883,  p.  275. 

3  Op.  tit.,  p.  4. 

21 


22  THE   HEARING   OF  PRIMITIVE   PEOPLES 

The  manufacturers  send  out  with  each  Edelmann8  whistle  a 
chart  giving  the  pipe  length,  the  mouth  width,  and  the  vibration 
frequency  corresponding  to  each  of  some  twenty  different  tones, 
ranging  in  pitch  from  that  represented  by  a  vibration  rate  of  6,000 
to  that  represented  by  a  rate  of  50,000  double  vibrations  to  the 
second.  It  is  claimed  that  each  whistle  has  been  graduated  inde- 
pendently and  empirically  at  the  factory,  and  that,  for  each  tone, 
that  mouth  width  was  selected  by  trial  and  practise  which  would 
produce  a  note  of  optimum  purity  and  strength. 

In  the  chart  sent  out  with  the  whistle  which  fell  into  my  hands, 
it  appeared  that  the  graduations  for  those  tones  lying  between  e3 
and  e8  had  been  made  with  a  uniform  mouth  width  of  0.75  mm. 
With  the  whistle  so  adjusted,  those  tones  lying  in  the  region  of  e6 
were  pure,  clear  and  free  from  that  peculiar  harshness  which  results 
when  a  considerable  quantity  of  air  escapes  with  the  tones.  The 
contrary,  however,  was  true  when  the  whistle  cavity  was  diminished 
for  the  production  of  tones  in  the  region  of  e8.  These  latter  tones 
were  decidedly  harsh.  This  harshness  was  obviously  due  to  the 
accompaniment  of  air  puffs,  which  escaped  with  the  tones.  They 
stood  out  so  prominently  as  to  confuse  even  the  most  careful  subjects, 
and  must  have  proven  a  very  distracting  element  to  children,  and 
especially  to  the  primitive  peoples.  It  therefore  seemed  advisable 
to  vary  the  adjustment  from  that  prescribed  in  the  chart  sent  out 
with  the  instrument  even  if  it  would  necessitate  an  entire  re-gradua- 
tion. 

After  careful  experimentation  with  the  assistance  of  Professor 
Woodworth,  a  mouth  width  was  hit  upon  which  give  admirable 
results  for  all  tones  from  e5  upwards.  Indeed,  so  free  was  the  tone 
from  wind  blasts,  that  when  the  threshold  range  was  passed,  no  audi- 
tory stimuli  of  any  character  were  sensed  as  coming  from  the 
whistle.  This  mouth  width  was  0.55  mm.  It  chanced,  however,  that 
the  resulting  tone  was1  predominantly  the  first  overtone  instead  of 
the  fundamental,  but,  since  the  fundamental  tone  was  inaudible 
except  for  vibration  rates  between  ten  and  fifteen  thousand,  it  was 
thought  not  to  be  a  particularly  disturbing  factor.  All  the  meas- 
urements at  the  Exposition,  consequently,  except  those  where  the 
upper  limit  was  found  to  be  extremely  low,  were  made  with  a  con- 
stant mouth  width  of  0.55  mm.  This,  to  be  sure,  rendered  the 
table  which  accompanied  the  whistle  entirely  worthless.  A  wholly 
new  set  of  graduations  must  be  made  to  meet  the  new  conditions. 

•The  Edelmann  whistle  used  in  my  tests  was  kindly  loaned  to  me  by  the 
C.  H.  Stoelting  Co.,  38  W.  Randolph  Street,  Chicago,  for  the  double  purpose  of 
exhibition  and  experimentation. 


THE    INSTRUMENT    AND    ITS    GRADUATION  23 

To  carry  on  such  an  extended  series  of  experiments  called  for  more 
time  and  more  elaborate  preparations  than  it  was  possible  to  insti- 
tute at  St.  Louis.  I  therefore  allowed  this  work  to  await  my  return 
to  Columbia  University  after  the  Exposition  had  closed. 

While  collecting  the  data,  the  measurements  were  tabulated  in 
terms  of  mouth  width  and  pipe  length,  from  which  it  was  possible 
readily  to  transcribe  them  into  terms  of  vibration  frequencies,  and 
into  musical  nomenclature  when  desirable.  The  graduation  of  the 
whistle  was  a  difficult  task.  In  the  work  of  determining  the  vibra- 
tion frequencies  corresponding  to  the  different  pipe  lengths  em- 
ployed in  the  actual  test,  several  devices  were  tried  with  varying 
degrees  of  success.  It  was  found  especially  difficult  to  devise  any 
rotating  system  of  sufficient  speed  and  delicacy  to  register  satis- 
factorily disturbances  of  a  sensitive  flame  for  such  rapid  vibration 
rates  as  those  from  15,000  to  40,000  D.  V.  The  optical  method  for 
registering  vibrations  used  in  physical  laboratories,  however,  was 
tried  for  some  of  the  lower  pitches,  but  even  here  the  figures  were 
by  no  means  wholly  satisfactory,  by  reason  of  the  inaccuracies  in 
determining  the  speed  of  the  rotating  system,  the  sliding  of  parts, 
etc.,  etc. 

The  most  satisfactory  device  for  making  the  graduations,  because 
the  most  accurate  and  objective,  proved  to  be  the  "dust  figure" 
method  of  Kundt,  first  adapted  to  the  use  of  tubes  of  small  bore  by 
Schwendt.4  The  Kundt  dust  figures  are  illustrated  and  described 
in  all  general  texts  on  acoustics;  hence,  they  require  no  elaborate 
description  in  this  place.  The  dust  figure  method  is  the  one, 
moreover,  which  is  employed  at  the  factory  for  standardizing  the 
Edelmann  whistles  before  they  are  sent  out.  The  modifications 
which  are  essential  to  adapt  this  method  to  tones  as  high  as  those 
employed  for  testing  the  upper  limit  of  audibility  are  significant  as 
to  detail  and  procedure.  It  is  unnecessary  to  enter  here  into  a 
description  of  the  mode  of  procedure  in  anything  like  a  detailed  way. 
Something  requires  to  be  said,  however,  with  reference  to  some  of 
the  difficulties  which  are  encountered. 

One  of  the  first  essentials  with  regard  to  the  dust  figure  method 
is  that  the  tubes  used  for  resonance  chambers  shall  be  of  optimum 
dimensions.  A  series  of  tubes  varying  in  length  and  bore  are 
consequently  necessary  to  secure  satisfactory  results.  For  evalu- 
ating the  most  acute  tones,  I  drew  out  some  very  thin  tubes  to  a 
bore  of  2  mm.  and  a  length  of  26  mm. — just  long  enough  to  allow 
for  the  formation  of  five  or  six  half -wave  lengths,  that  is,  for  five 

'Pfluger's  Arch.  75:  546.    1899. 


24  THE   HEARING   OF  .PRIMITIVE    PEOPLES 

crests  and  as  many  troughs.  It  is  quite  essential  that  a  number 
of  these  artificial  wave  troughs  and  crests  be  formed  if  the  work  is  to 
be  at  all  delicate,  since,  in  making  the  actual  measurements  of  the 
length  of  the  several  waves,  accuracy  is  enhanced  if  the  span 
covered  by  several  half  waves  is  measured  with  the  aid  of  calipers 
and  the  figure  thus  obtained  divided  by  their  number  to  secure  the 
length  of  a  single  wave.  Tubes  with  bores  of  from  6.0  mm.  to  10 
mm.  and  lengths  from  100  to  250  mm.  were  used  for  tones  of  the 
sixth  and  the  lower  third  of  the  seventh  octaves  (c6-e7),  and  still 
larger  tubes  for  the  tones  of  still  lower  pitch  values.  Just  enough 
of  the  lycopodium  powder,  which  had  been  previously  carefully 
dried,  to  cover  the  bottom  of  the  tube,  was  evenly  distributed  along 
its  entire  length.  The  tube  was  then  slightly  turned  so  as  to  raise 
the  powder  to  one  side.  This  facilitates  the  formation  of  dust 
figures,  the  aerial  disturbance  within  causing  the  dust  to  fall,  and 
while  falling,  to  collect  at  the  points  of  rarefaction  within  the  reson- 
ance chamber. 

In  making  dust  figures,  it  is  necessary  that  the  resonance  tubes 
be  kept  free  from  extraneous  vibratory  influences,  else  the  resulting 
dust  figures  will  be  confused  and  impossible  to  interpret.  To  avoid 
jars  of  all  kinds,  I  had  the  tubes  carefully  clamped  between  large 
pieces  of  cork,  which  took  up  most  of  the  disturbances  transmitted 
to  them.  Then  to  make  as  much  as  possible  of  the  sound  energy 
leaving  the  whistle  enter  the  tubes,  the  whistle  mouth  was  brought 
as  close  to  the  mouth  of  the  resonance  tube  as  possible,  and,  to 
further  facilitate  the  movement  of  air,  the  ends  of  the  tubes  adjacent 
to  the  source  of  sound  were  flared  into  a  funnel  form  whose  widest 
diameter  was  about  15  mm.  When  everything  proceeded  favorably, 
satisfactory  dust  figures  generally  resulted  in  from  ten  to  fifteen 
minutes,  but  failures  and  disasters  were  frequent.  Indeed,  much 
patience  and  repetition  were  required  to  secure  perfectly  reliable 
results,  frequently  as  many  as  six  or  seven  trials  being  necessary  to 
get  anything  like  a  satisfactory  measurement.  It  was  essential  that 
each  graduation  be  the  average  of  as  many  determinations  as  pos- 
sible to  eliminate  chance  results.  My  data,  in  every  instance,  are  the 
average  of  five  or  more  determinations. 

Let  us  assume  that  the  dust  figures  have  formed  in  the  resonance 
tube.  Knowing  the  distance  between  two  adjacent  wave  crests,  it  is 
a  simple  matter  to  compute  the  vibration  frequency  of  the  tone  that 
gave  rise  to  the  dust  figures.  The  result  is  accomplished  directly  by 
a  simple  formula, 


THE   INSTRUMENT   AND    ITS    GRADUATION  25 

where  "N"  represents  the  vibration  frequency,  "Va"  the  velocity 
of  sound  in  air  at  the  temperature  prevailing  at  the  time  the  meas- 
urement is  made,  and  "L"  represents  one  half  wave-length,  or  the 
distance  encompassed  by  two  adjacent  wave  crests.  The  "Va" 
implies  a  temperature  correction.  At  0°  Centigrade,  under  ordinary 
barometric  pressures  for  this  latitude,  sound  has  a  velocity  of 
330.7  M.  per  second.  To  secure  the  corrected  value  of  eeVa"  for 
any  given  temperature,  I  used  the  well-known  formula  of  Kayser 
and  Kirchoff,5 

Va  =  330.7  V  1  +  0.00376  t<* 

During  the  summer  of  1904,  within  doors  on  the  shady  side  of  a 
building  the  temperature  varied  (according  to  the  United  States 
Weather  Bureau  reports6),  between  17°  and  37°  C.  Our  hearing 
tests,  however,  were  made  in  a  basement  where  the  prevailing 
temperature  was  lower,  and  unfortunately  we  have  no  record  of 
this  during  this  period.  Still  the  difference  between  this  and  the 
above,  I  think,  does  not  amount  to  a  figure  to  be  significant.  My 
corrections  were  made  on  the  basis  of  the  Weather  Bureau  statistics.6 

In  the  sound-proof  room  of  the  Psychological  Laboratory  of 
Columbia  University  where  the  work  of  graduation  was  done,  the 
temperature  remained  quite  uniformly  at  22.2°  C.,  making  the 
velocity  of  sound  approximately  344  M.  per  second. 

Temperature  variations  can  not  well  be  neglected  in  making 
tests  for  the  upper  limit  of  hearing  with  such  a  device  as  the  Edel- 
mann  whistle,  if  results  be  sought  which  aim  to  be  more  than  ap- 
proximately correct.  Taking  the  lower  and  upper  extremes  of 
temperature,  during  the  days  that  my  hearing  measures  were  made, 
and  making  the  necessary  corrections,  a  whistle  cavity  length  of 
1.3  mm.  and  mouth  width  of  0.55  mm.  would  give  a  vibration  fre- 
quency of  40,840  D.  V.  and  42,054  D.  V.  respectively.  This  varia- 
tion is  certainly  sufficient  to  be  quite  significant,  especially  in  view 
of  the  fact  that  tests  on  the  different  peoples  were  made  during 
different  seasonal  conditions.  With  regard  to  most  of  the  data 
relating  to  the  Filipinos,  the  correction  was  especially  necessary, 
because  the  season  had  so  far  advanced  when  these  people  were 
measured  that  the  rooms  had  to  be  heated  artificially,  and  the 
temperature,  which  was  almost  uniformly  22°  C.  differed  markedly 

6 See  Wiillner's  "Experimental  Physik »   (1894),  1:  931. 

8 1  was  able  to  secure  from  the  office  of  the  U.  S.  Weather  "Bureau  at 
St.  Louis  temperature  and  humidity  readings  taken  at  each  hour  of  the  day, 
for  a  period  covering  that  included  by  the  taking  of  the  hearing  records.  From 
these  figures  I  calculated  the  true  value  of  "  Va  "  for  each  hearing  record  made. 


26  THE   HEARINa  OF  PRIMITIVE   PEOPLES 

from  that  prevailing  during  the  hot  summer  weather  when  the  data 
on  Indians  and  whites  was  collected. 

Conditions  at  the  Exposition  made  it  necessary  to  employ  a  wind 
blast  supplied  from  the  hand  bulb,  which  accompanies  the  whistle. 
Some  such  constant  pressure  device  as  that  of  Whipple7  was  con- 
templated, but  there  was  so  much  delay  occasioned  by  the  failure 
of  the  apparatus  to  arrive  and  the  general  equipment  of  the  labora- 
tory to  be  provided,  that  many  of  the  tests  of  the  upper  range  of 
hearing  were  made  before  such  an  equipment  might  have  been  in- 
stalled. Consequently,  to  keep  the  conditions  under  which  the  tests 
were  conducted  as  nearly  uniform  as  possible,  the  hand  bulb  method 
of  blowing  the  whistle  was  permanently  adhered  to.  Edelmann 
holds  that  with  a  whistle  of  the  type  I  used,  the  pitch  of  the  tone  is 
only  slightly  dependent  on  the  wind  pressure  employed.8  This 
statement,  however,  can  be  only  partially  true,  and  indeed  is  ap- 
plicable only  to  a  certain  range  of  variation  about  the  optimum  wind 
blast  for  blowing  it. 

To  investigate  the  influence  of  a  variable  wind  blast  to  some 
extent,  I  improvised  a  wind  pressure  device  which  allowed  of  dif- 
ferences in  the  force  of  the  blast.  An  ordinary  wet  spirometer, 
found  in  the  Columbia  University  Psychological  Laboratory,  was 
weighted  to  the  required  wind  pressure  by  loading  it  with  slugs  of 
iron ;  then,  with  an  ordinary  foot  bellows,  the  quantity  of  air  in  this 
reservoir  was  kept  constant.  As  in  all  such  experiments,  a  water 
manometer  or  U-tube,  was  inserted  in  the  lead  as  close  to  the  whistle 
as  convenient  to  measure  the  pressure  of  the  air  blast  passing  into 
the  whistle.  But  before  allowing  the  air  to  pass  through  the 
whistle,  it  was  made  to  flow  through  a  drying  device ;  a  bottle  filled 
with  the  crystals  of  calcium  chloride,  by  which  the  moisture  was, 
so  far  as  possible,  removed  inasmuch  as  moisture  in  the  air  tends  to 
interfere  seriously  with  the  formation  of  the  ly  cop  odium  dust  figures 
in  the  resonance  chambers. 

The  cavity  length  of  the  whistle  being  1.3  mm.  and  mouth  width 
0.55  mm.,  with  a  constant  wind  pressure  indicated  by  40  mm.  of 
water  in  the  U-tube,  the  resulting  tone  was  too  faint  and  weak  to 
produce  satisfactory  dust  figures.  It  sounded  of  uncertain  piteh 
and  was  by  no  means  pure. 

When  the  wind  blast  showed  100  mm.  of  water  in  the  U-tube,  the 
tone  was  clear  but  observably  lower  than  when  the  whistle  was 
blown  by  the  rubber  bulb.  With  the  wind  pressure  increased  to 
500  mm.  of  water,  the  tone  came  forth  clear  and  piercing.  My 

T"A  Compressed  Air  Device,  etc.,"  Amer.  J.  of  Psychol.  14:   107.    1903. 

*Annalen  d.  Physik,  4  Folge,  11.    1900. 


THE   INSTRUMENT   AND   ITS    GRADUATION  27 

subjective  judgment  was  that  the  pitch  was  the  same  as  that  pro- 
duced by  the  use  of  the  bulb. 

The  table  below  shows  the  result,  in  terms  of  wave  lengths  and 
vibration  frequencies,  for  a  number  of  different  wind  pressures 
employed : 

Wind  Pressure  :  Wave  Lengths  in  mm.  Pitch  Values 

mm.  of  water  Average  of  5  determinations  D.  V. 

40  A  faint  tone — too  weak  to  produce  dust  figures 

100  16.268  21,330 

500  8.33  41,217 

1,000  8.724  39,460 

Rubber  bulb  8.428  40,840 

These  averages  were  obtained  from  the  following  individual  de- 
terminations : 

Pressure — 100  mm.  of  Water 

3  crests  measured  23  mm.  Wave  length  15.34  mm. 

2  17  17.00 

2  19  19.00 

3  22  14.66 

3  23  15.34 

Average  wave  length  16.248  mm. 

500  mm.  of  Water 

5  crests  measured  21  mm.  Wave  length  8.4  mm. 

4  15  7.5 

4  18  9.0 

6  25  8.34 

5  21  8.4 

Average  wave  length  8.33  mm. 

1,000  mm.  of  Water 

4  crests  measured  19  mm.  Wave  length  8.5  mm. 

6  •         26  8.66 
6   .                              23  7.66 

5  22  8.8 

4  18  9.0 

Average  wave  length  8.524  mm. 

The  Bulb 

5  crests  measured  19  mm.  Wave  length  7.6  mm. 

4  17.5  8.75 

6  25  8.33 
6                                  26                                                    8.66 

5  22  8.8 

Average  wave  length  8.428  mm. 

These  figures  are  in  general  in  agreement  with  those  obtained  by 
Dr.  Charles  Myers,  in  investigating  a  similar  problem  with  the 


28  THE   HEARING   OF  PRIMITIVE   PEOPLES 

Gallon  whistle.  It  is  to  be  noted,  however,  that  a  wind  pressure  of 
1,000  mm.  of  water,  gave  a  tone  which  is  actually  lower  than  that 
produced  by  a  wind  pressure  of  500  mm.  of  water,  a  fact  which  does 
not  accord  with  Dr.  Myers's9  experimental  conclusions.  His  experi- 
ments lead  him  to  believe -that  the  pitch  of  the  whistles  increases 
regularly  with  increase  of  air  blast.  The  difference  in  favor  of  the 
lower  wind  pressure  found  by  me,  I  believe,  however,  is  not  signifi- 
cant in  that  I  do  not  think  it  exceeds  the  limits  of  the  accuracy  of 
the  method.  It  is  to  be  further  noted  that  with  the  bulb,  the 
figures  do  not  differ  materially  from  those  with  a  wind  pressure 
of  500  mm.  and  1,000  mm.  So  far  as  I  was  able  to  determine,  the 
bulb  gives  approximately  a  pressure  of  800  mm.  of  water  though 
with  a  pressure  of  so  short  duration  it  is  difficult  to  evaluate  ac- 
curately the  total  force  given  out,  with  the  means  at  my  command. 

Inasmuch  as  in  all  my  investigations  the  bulb  supplied  the  wind 
blast,  it  is  the  graduations  in  which  the  same  source  of  wind  pressure 
was  used  that  concern  us  chiefly.  Indeed,  for  this  reason,  in  all 
of  the  work  of  standardizing  the  instrument,  from  which  the  tables 
to  follow  were  made,  the  rubber  bulb  alone  was  employed.  When 
using  the  hand  bulb  in  the  making  of  the  graduations,  an  effort 
was  made  to  reproduce  as  nearly  as  possible  the  conditions  as  they 
obtained  in  taking  the  original  hearing  records.  That  the  condi- 
tions were  more  than  approximately  reproduced  and,  moreover, 
that  with  the  use  of  the  bulb,  fairly  constant  conditions  can  be 
maintained  from  day  to  day,  is  borne  out  by  the  rather  uniform 
character  of  the  data  secured.  Were  one  unable  to  give  relatively 
constant  and  uniform  blasts  to  the  whistle  in  blowing  it  with  the 
hand  bulb,  some  marked  differences  in  the  vibration  frequencies  of 
the  tones  produced  would  result,  and  would  show  in  the  dust  figures. 
It  is  significant  that  such  was  not  found  to  be  the  case,  and  that 
no  greater  differences  in  the  character  of  the  dust  disturbances  were 
experienced  when  the  hand  bulb  supplied  the  air  than  when  the  air 
came  from  a  uniform  and  constant  pressure  source,  as  is  shown  in 
the  foregoing  tables.  To  illustrate  this  point,  I  shall  present  some 
typical  measurements  in  which  the  hand  bulb  was  employed.  As 
too  much  space  would  be  required  to  present  the  individual  measure- 
ments for  the  graduations  of  the  whole  series  of  whistle  lengths  used 
in  the  original  tests,  I  will  content  myself  with  two  samples  selected 
at  random. 

In  the  following  series,  the  length  of  the  whistle  bore  measured 
1.5  mm.,  the  mouth  width  being  0.55  mm.: 

•"The  Pitches  of  Galton  Whistles,"  J.  of  Physiol.  28:  417.    1902. 


THE   INSTRUMENT   AND   ITS    GRADUATION  29 

2  crests  measured     9.2  mm.  Wave  length  9.2  mm. 

12  57.1  9.52 

12  52.81  8.8 

20  87.34  8.73 

14  65.41  9.33 

Average  wave  length  9.116  mm. 
Vibration  frequency  37,560  D.  V. 

In  the  next  series,  the  cavity  length  of  the  whistle  was  2.2  mm., 
the  mouth  width  remaining  the  same  as  in  the  preceding  experiment : 

2  crests  measured  16.0  mm.  Wave  length  10.66  mm. 
4                                 22.3  11.15 

9  44.1  9.08 

6  31.2  10.04 

3  15.4  10.26 

Average  wave  length  10.45  mm. 
Vibration  frequency  30,270  D.  V. 

These  two  sets  of  measurements  are  in  every  way  typical  of  all 
that  were  made  and  indicate  about  the  same  degree  of  variation 
between  the  individual  determinations  as  was  experienced  on  the 
average.  The  same  procedure,  as  in  these  samples,  was  followed  for 
every  whistle  length  employed  in  the  original  measurements.  The 
accompanying  table  gives  the  vibration  frequencies  corresponding 
to  each  whistle  length  as  empirically  determined  by  aid  of  the 
Kundt-Schwendt  resonance  method. 

In  this  table  the  distance  between  the  lips  of  the  whistle  remained 
uniformly  at  0.55  mm.  The  average  wave-length  of  the  several 
determinations  has  been  omitted  in  each  case  since  it  would  afford 
no  information  vital  to  an  interpretation  of  the  figures  presented : 

Length  of  whistle        Vibration  Frequencies  Length  of  whistle      Vibration  Frequencies 

cavity  in  mm.  (Complete  Vibrations)  cavity  in  mm.         (Complete  Vibrations) 

1.2  42,960  2.5  28,048 

1.3  40,840  2.6  27,448 

1.4  39,220  2.7  26,854 

1.5  37,560  2.8  26,264 

1.6  36,360  2.9  25,724 

1.7  35,100  3.0  25,212 

1.8  34,000  3.1  24,754 

1.9  33,060  3.2  24,196 

2.0  32,180  3.3  23,020 

2.1  31,170  3.6  22,217 

2.2  30,270  3.8  20,973 

2.3  29,508  4.0  18,490 

2.4  28,766 


CHAPTER   IV 

DATA  COLLECTED  ON  THE  UPPER  LIMIT 

DURING  the  earlier  months  of  the  Exposition,  while  we  were 
getting  our  bearings,  equipping  our  laboratories,  and  installing  our 
apparatus  which  was  somewhat  tardy  in  arriving,  we  spent  our  time 
amusing  the  public  and,  incidentally  accumulating  data  on  some 
few  tests.  For  the  most  part  we  limited  ourselves  to  a  single  test 
and  measured  as  many  individuals  as  we  could  in  this  one  particular 
only.  In  consequence,  I  was  enabled  to  secure  considerable  material 
relating  to  the  upper  threshold  of  hearing.  Unfortunately  these 
data  had  to  be  secured  under  somewhat  unfavorable  conditions,  in 
that  the  test  was  always  made  in  the  presence  of  a  crowd.  The 
sound  room  had  then  not  yet  been  completed  and  there  were  many 
distracting  noises  that  might  have  tended  to  distort  the  results  to 
some  extent.  On  the  whole,  notwithstanding,  I  believe  the  data 
satisfactory,  since  a  comparison  of  this  material  with  some  secured 
on  whites  in  the  sound  room  showed  no  significant  differences. 

The  individuals  were  tested  one  at  a  time.  The  Edelmann 
whistle  was  held  twelve  inches  from  the  subject's  ear  and  blown; 
the  other  ear  meanwhile  being  closed  by  pressing  the  tip  of  the 
finger  into  the  auditory  meatus.  At  first  the  pipe  was  so  adjusted 
that  a  tone  resulted  whose  pitch  was  so  low  as  to  be  easily  sensed 
by  all  ears.  The  pitch  was  then  gradually  raised  until  a  point  was 
reached  where  the  tone  was  no  longer  audible.  A  reading  was  then 
taken  and  recorded  for  the  last  audible  sound.  Beginning  with  an 
inaudible  tone,  the  pitch  was  now  lowered  until  it  could  again  just 
be  sensed  and  this  whistle  length  recorded.  The  average  of  the  two 
tabulations,  if  a  difference  existed— and  there  usually  did— was 
taken  as  the  measure  of  the  upper  limit  of  the  person  tested.  Each 
ear  was  tested.  Almost  without  exception,  the  right  ear  was  the 
one  first  examined. 

In  the  measures  on  primitive  peoples,  the  procedure  was  in  all 
respects  essentially  the  same  as  just  outlined,  except  that  the  tests 
were  made  within  a  specially  constructed  booth.1  Although  this 

1This  booth  was  constructed  in  one  corner  of  a  room  of  our  suite,  which 
had  been  closed  to  the  public,  being  set  apart  by  us  for  making  such  measure- 
ments as  required  privacy.  The  dimensions  of  the  booth  were  approximately 
six  by  nine  feet,  and  seven  feet  in  height.  On  two  sides  the  heavy  stone  and 

30 


DATA    COLLECTED    ON    THE    UPPER   LIMIT  31 

room  was  not  completely  sound-proof,  it  did  exclude  extraneous 
noises  sufficiently  well  to  keep  the  subject  free  from  distractions. 
To  contribute  still  further  to  this  same  end,  the  person  tested  was 
kept  in  the  dark  and  his  back  turned  to  the  experimenter,  in  order, 
so  far  as  possible,  to  exclude  visual  stimuli  and  allow  the  subject's 
mind  to  concentrate  wholly  upon  the  auditory  sensations  presented 
to  him.  Moreover,  the  subject  was  seated  in  a  chair,  in  as  com- 
fortable a  position  as  possible.  In  other  words,  I  attempted  to  make 
the  external  conditions  as  suitable  as  could  conveniently  be  done  for 
sensing  the  auditory  stimuli  and  consequently  securing  the  most 
nearly  normal  results. 

By  way  of  check,  a  record  was  made  of  my  own  hearing  im- 
mediately following  that  of  each  individual  tested.  Conditions  made 
it  necessary  for  me  to  make  personally  the  test  of  my  own  hearing. 
Still  I  do  not  think  that  the  source  of  error  arising  from  this  method 
is  really  significant.  Of  course,  the  element  of  expectancy  was  some- 
thing of  a  factor  so  that  there  might  have  entered  into  the  experi- 
ments auditory  images  which  it  were  easily  possible  to  confuse  and 
mistake  for  the  stimulus  at  a  time  when  it  was  really  inaudible.  I 
have,  however,  practically  no  auditory  imagery,  at  least,  I  have  never 
been  able  to  observe  any  in  myself,  so  it  is  scarcely  possible  that 
images  of  sufficient  intensity  to  be  confused  with  even  faint  stimuli 
should  have  arisen  under  the  circumstances  just  noted.  In  any 
event,  the  factors  concerned  with  the  personal  test  did  not  vary  from 
day  to  day  or  from  hour  to  hour,  and  hence  are  not  significant  on 
the  whole.  In  this  connection  may  be  mentioned  the  need  for  this 
check,  discovered  during  the  time  the  tests  were  being  made.  It 
frequently  occurred  that  the  whistle  became  partially  clogged  with 
bits  of  rubber,  or  other  matter  coming  from  the  inside  of  the  rubber 
bulb.  This  clogging  had  the  effect  of  lowering  the  pitch  of  the 
upper  tones  from  a  fifth  to  an  octave,  although  otherwise  no  ap- 
parent change  in  the  character  of  the  tones  resulted,  so  that  had  it 
not  been  for  the  personal  check-test,  the  subject  would  have  received 
an  unfairly  high  rating. 

brick  walls  of  the  building  served  to  exclude  the  most  penetrating  sounds. 
Although  the  remaining  sides  were  of  wood,  the  walls  were  double,  the  space 
of  about  four  inches  between  the  two  being  filled  with  sawdust.  Sawdust  to 
the  depth  of  six  to  eight  inches  also  covered  the  roof  while  the  whole  booth 
rested  in  a  bath  of  sawdust  in  order  to  exclude  any  sounds  which  might  be 
conducted  into  it  through  the  cement  floors  of  the  building.  Entrance  was  made 
through  a  single  padded  door,  and  the  sole  illumination  came  from  an  incan- 
descent electric  bulb  which  was  suspended  over  the  apparatus.  The  arrange- 
ment was  such  as  to  exclude  extraneous  sounds  entirely  for  all  practical 
purposes. 


32  THE   HEARING   OF  PRIMITIVE   PEOPLES 

It  is  unnecessary  to  name  all  the  factors  and  considerations  which 
entered  vitally  into  the  making  of  the  tests,  but  there  is  still  one 
which  requires  to  be  mentioned.  This  relates  to  the  ear's  suscepti- 
bility to  fatigue.  Observers  are  unanimous  in  their  experience  with 
respect  to  this  point.  Professor  Seashore2  has  remarked  in  con- 
nection with  his  audiometer  that  to  be  satisfactory  for  testing  chil- 
dren, owing  to  the  presence  of  fatigue,  a  device  must  be  employed 
which. will  make  it  possible  to  complete  the  test  in  not  to  exceed 
two  minutes.  Especially  with  subjects  who  are  unaccustomed  to 
making  introspective  observations,  it  is  found  that  tones  die  out 
and  are  inaudible  long  before  threshold  values  are  reached.  Par- 
ticularly is  this  true  where  continuous  tone  devices  are  employed  in 
making  auditory  measurements  such,  for  example,  as  the  tuning 
fork,  the  sounding  rod,  or  the  Galton  or  Edelmann  whistle,  blown 
by  some  constant  and  continued  air  supplying  device.  For  this 
very  reason  such  devices  and  means  for  testing  the  range  of  audi- 
tion are  unserviceable.  The  Edelmann  whistle  blown  by  means  of 
the  bulb  with  its  short,  quick  sound  obviates  all  this  difficulty.  It  is 
a  difficulty,  too,  which  can  not  be  overlooked  with  safety,  especially 
in  dealing  with  children  and  primitive  peoples. 

The  Measurements: — We  shall  now  turn  directly  to  the  data 
regarding  racial  differences  in  the  upper  limit  of  hearing.  In  Table 
I.  are  presented  the  figures  representing  the  averages  for  both  the 
right  and  left  ears.  In  the  first  column  are  indicated  (1)  the  num- 
ber of  individuals  constituting  each  group  examined;  and  in 
parallel  columns;  (2)  the  averages;  (3)  the  average  of  the  devia- 
tions from  each  average;  and  (4)  the  standard  deviation,  of  each 
group.  From  these  data  it  is  possible,  without  difficulty,  to  compute 
directly  any  of  the  different  variability  coefficients  desired,  and  in 
consequence,  the  reliability  of  each  average,  and  the  probability  of  a 
difference  between  any  two  groups.  Owing  to  the  fact  that  among 
the  Filipinos,  the  Pigmies,  Patagoniaus  and  Cocopa,  there  were  no 
women  tested,  the  data  have  not  been  separated  so  as  to  show  the 
influence  of  sex,  except  that  relating  to  whites. 

In  tables  II.  and  III.  the  individual  records  are  distributed,  so 
as  to  present  in  parallel  columns  a  picture  of  the  distribution  of  the 
individuals  of  each  group  examined.  These  tables  represent  the 
figures  for  both  the  right  and  the  left  ears.  In  Table  IV.  is  pre- 
sented a  distribution  of  the  cases  according  to  age,  for  the  three 
most  numerous  groups  measured.  These  again  have  been  placed 
in  parallel  columns  to  afford  a  more  ready  comparison,  and  to  give 

2  Univ.  of  Iowa  Studies,  2:  55.    1899. 


DATA    COLLECTED    ON    THE    UPPER   LIMIT  33 

in  pictorial  form  the  relations  which  the  different  groups  sustain  to 
each  other  in  this  respect.  For  the  smaller  groups,  the  ages  will 
be  presented  in  connection  with  their  discussion. 


TABLE    I 

UPPER  LIMIT  OF  AUDIBILITY 
Racial  Differences  as  Shown  by  Averages 


No. 

Right  Ear 

Left  Ear 

Average 

A.  D.» 

S.  D.* 

Average 

A.D.3 

S.  D.* 

Whites.    . 

156 
63 
97 
10 

7 
7 
6 
3 

32,285  D.  V. 
31,975      " 
29,916      " 
32,123      " 
28,846      " 
28,269      " 
33,223      " 
30,240      " 

2271 
2190 
1755 
827 
1666 
1209 
2071 
3240 

2344 
2663 
2180 
977 
1873 
1413 
2468 
3551 

33,087  D.  V. 
31,580      " 
29,886      " 
31,794      « 
29,529      " 
27,571      " 
34,081      " 
28,630      " 

1891 
2460 
1737 
1408 
2946 
819 
3212 
2366 

2482 
3028 
2089 
1566 
3199 
852 
3428 
2592 

Indians 

Filipinos 

Cocopa.     .  .  . 

A  inns  

Vancouvers  
Pigmies  

Patagonians  

TABLE    II 

RIGHT  EAB — UPPEB  LIMIT  OF  HEARING 
Distribution  of  Individual  Cases 


Vibration 
Frequency 

Whistle 
Length 

Whites 

Indians 
from 
School 

Christian 
Filipi- 
nos 

Cocopa 
Indians 

Ainu 

Van- 
couver 
Indians 

Pigmy 

Patagonian 
Indians 

42,960 

1.2 

1 

_ 

_ 

_ 

_ 

__ 

40,840 

1.3 

0 

— 













39,220 

1.4 

3 

1 

— 









___ 

37,560 

1.5 

8 

— 

— 







1 

__ 

36,360 

1.6 

9 

6 





__ 

^_ 

__ 



35,100 

1.7 

10 

6 

2 



— 



1 

1 

34,000 

1.8 

15 

4 

2 

1 



__ 



33,060 

1.9 

18 

6 

4 

2 



__ 

1 



32,180 

2.0 

26 

6 

11 

1 





1 



31,170 

2.1 

20 

12 

14 

4 

1 



1 

__ 

30,270 

2.2 

18 

8 

20 



2 

1 

1 



29,508 

2.3 

6 

3 

10 

__ 

1 

1 



28,766 

2.4 

6 

5 

5 



2 



1 

28,048 

2.5 

7 

3 

10 



1 

1 

__ 

27,448 

2.6 

3 

1 

2 



1 

__ 



26,854 

2.7 

3 

1 

5 

___ 

2 



1 

26,264 

2.8 

2 

1 

3 







25,724 

2.9 

1 

1 

5 











25,212 

3.0 

— 

— 





1 

- 



__ 

24,754 

3.1 

— 

— 





__ 

__ 



24,196 

3.2 

— 

1 

1 

1 



__ 





23,020 

3.4 

— 

1 

— 











22,217 

3.6 

— 

1 





__ 







20,973 

3.8 

— 





1 

__ 







18,490 

4.0 

— 

— 

— 

— 

— 

— 

— 

8  A.  D. — Average  Deviation. 

*  S.  D.— Mean  Square  Deviation. 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


TABLE    III 

LEFT  EAB 

Distribution  of  Individual  Cases 


Vibration 
Frequency 

Whistle 
Length 

Whites 

Indians 
from 
School 

Christian 
Filipi- 
nos 

Cocopa 
Indians 

Ainu 

Van- 
couver 
Indians 

Pigmy 

Patagonian 
Indians 

42,960 

.2 





— 

— 

— 

— 

— 

— 

40,840 

.3 

— 

— 

— 

— 

— 

— 

— 

— 

39,220 

.4 

1 

1 

— 

— 

— 

— 

1 

— 

37,560 

.5 

8 

2 

— 

— 

— 

— 

1 

— 

36,360 

.6 

3 

2 

— 

— 

— 

— 

— 

— 

35,100 

.7 

9 

5 

— 

— 

— 

— 

1 

— 

34,000 

1.8 

14 

8 

1 

— 

— 

— 

— 

33,060 

1.9 

18 

6 

6 

1 

1 

— 

— 

— 

32,180 

2.0 

9 

4 

11 

— 

2 

— 

— 

1 

31,170 

2.1 

11 

11 

21 

3 

— 

— 

2 

— 

30,270 

2.2 

5 

3 

10 

1 

— 

— 

1 

— 

29,508 

2.3 

2 

11 

13 

1 

— 

— 

— 

— 

28,766 

2.4 

5 

0 

7 

— 

1 

2 

— 

— 

28,048 

2.5 

•2 

4 

5 

— 

— 

1 

— 

— 

27,448 

2.6 

— 

1 

5 

— 

— 

— 

— 

1 

26,854 

2.7 

— 

1 

5 

— 

1 

4 

— 

— 

26,264 

2.8 

— 

1 

6 

— 

— 

— 

— 

1 

25,724 

2.9 

— 

3 

2 

— 

— 

— 

— 

— 

25,212 

3.0 

— 

— 

— 

— 

— 

— 

— 

— 

24,754 

3.1 

— 

— 

1 

— 

1 

— 

— 

— 

24,196 

3.2 

— 

1 

— 

— 

— 

— 

— 

— 

23,020 

3.4 

— 

— 

— 

— 

— 

— 

— 

— 

22,217 

3.6 

— 

— 

— 

1 

— 

— 

— 

— 

20,973 

3.8 

— 

1 

— 

— 

— 

— 

— 

— 

18,490 

4.0 

— 

— 

— 

— 

— 

— 

— 

— 

TABLE    IV 

TABLE  SHOWING  THE  NUMBEB  OF  PERSONS  OF  EACH  AGE  OF  THE  THREE  MOST 

NUMEROUS  GROUPS  OF  PEOPLE  MEASURED 
Ages     16    17    18    19    20    21    22    23    24    25    26    27    28    29    30 


12 


14 


12 


19 


Whites  .............     5 

Indians    (School)    ...   12 
Filipinos   ............     3 

Average  age:  Whites,  23  years,  5  months;  Indians,  19  years,  2  months; 
Filipinos,  21  years,  1  month. 


6 

11 

1 


10 
16 

8 


8 

12 
16 


14 

4 

20 


14 

2 

12 


13 

1 
5 


11 

1 
5 


10 
2 
2 


Reference  to  Table  I.  shows  that  of  Whites,  the  records  of  156 
individuals  were  included  in  this  study.  Owing  to  some  rather 
significant  changes,  that  occur  in  the  range  of  audibility  during  the 
earlier  and  later  years  of  life  as  has  been  already  indicated  by  the 
studies  of  Zwaardemaker,5  Alderton,  and  others,  it  was  thought 
advisable  to  include  in  these  data  only  the  records  of  those  in  early 
manhood  and  womanhood,  those  individuals  whose  ages  ranged 

•See  Alderton,  Arch,  of  Otol.  23:  171.    1894;  25:  45.    1896;  also  Zwaarde- 
maker, Ztschr.  f.  Psychol.  7:  10.    1894,  and  Arch.  f.  Ohrenhk.  32:  53;  35:  299. 


DATA    COLLECTED    ON    THE    UPPER   LIMIT  35 

from  sixteen  to  thirty  years.  During  these  years,  no  very  signifi- 
cant changies  have  been  discovered  in  the  respect  just  indicated.  I 
excluded  also,  not  only  in  case  of  the  whites  but  also  among  the 
other  races,  the  record  of  every  individual  who  had  noticed  particu- 
larly any  diminution  in  his  hearing  acuity.  Obviously  those  with 
defective  hearing  should  not  be  included  in  any  comparative  meas- 
ure of  the  hearing  function,  since  they  form  a  distinct  functional 
group  or  species. 

The  average  age  of  the  whites  was  found  to  be  23  years  and 
5  months.  About  one  third  of  them  were  older  than  25  years,  while 
one  fifth  only  were  younger  than  20.  The  majority,  therefore,  of 
the  Whites  used  here  for  comparative  purposes  were  between  the 
ages  of  twenty  and  twenty-five  years— men  and  women  in  the 
younger  years  of  adulthood,  at  a  period  of  life  most  favorable  for 
accurate  testing. 

On  the  average,  the  results  show  a  slight  superiority  of  the  left 
over  the  right  ear,  the  average  for  the  latter  being  33,087  D.  V.,  as 
against  32,285  D.  V.  for  the  former.  This  is  in  accord  with  the 
observations  of  Preyer  and  Fechner,  who  observe  that  the  left  ear 
is  superior  to  the  right  in  all  its  functions,  due,  they  believe,  to 
the  fact  that  human  beings  are  left  brained.  In  the  case  of  my 
own  measurements,  however,  much  may  have  had  to  do  with  the 
order  of  testing  the  two  ears.  During  these  tests,  the  right  ear  was 
almost  invariably  first  tested,  so  that  a  mental  element  arising  from 
practise  may  have  been  responsible  for  the  superiority  of  the  left 
ear.  If  instead  of  the  average  we  take  the  median  as  the  measure, 
the  difference  in  result  is  not  changed. 

The  reliability  of  the  averages,  which  may  be  directly  computed 
from  the  S.  D.  given  in  Table  I.,  is  such  as  to  indicate  that  the 
chances  are  about  ten  to  one  that  the  true  average  will  not  vary 
from  the  one  given  by  more  than  200  vibrations,  which  in  reality, 
is  within  the  range  of  instrumental  accuracy;  that  is,  the  true 
average  will  not  be  as  high  as  32,500  vibrations  to  the  second  or  as 
low  as  32,000. 

Reference  to  tables  II.  and  III.  will  show  that  the  distributions 
are  fairly  normal.  Exclusion  of  the  records  of  all  individuals  who 
had  experienced  some  hearing  defect  has  served  to  eliminate  the 
skewness  which  might  otherwise  be  looked  for  at  the  lower  end  of 
the  curve. 

INDIANS 

So  far  as  I  am  aware,  no  study  of  the  hearing  of  our  American 
Indian  has  ever  been  undertaken.  There  are,  to  be  sure,  in  the 
literature  relating  to  this  interesting  race  of  people,  some  general  ob- 


36  THE   HEARING   OF  PRIMITIVE   PEOPLES 

servations  of  a  wholly  unscientific  character  which,  for  the  most 
part,  attribute  to  the  savage  of  the  American  forest  and  plains,  a 
remarkable  sensory  acuity.  The  works,  for  example,  of  James  Feni- 
more  Cooper,  contain  statement  after  statement,  all  purporting  that 
the  Indian  has  ears  that  hear  so  keenly  that  he  is  able  to  detect 
sounds  in  the  forest  that  are  wholly  inaudible  to  the  ears  of  a  white 
man  most  favorably  gifted  in  this  respect.  And,  indeed,  whether 
from  the  popular  literature  relating  to  Indians,  or  from  a  pre- 
conceived notion  that  a  savage  ought  to  be  superior  to  civilized 
peoples  in  sensory  acuity,  the  opinion  generally  prevails  that  the 
ears  of  the  Indians  are  very  much  keener  than  are  those  of  the 
Whites.  No  doubt  much  of  this  conception  arises  from  the  belief  in 
what  is  commonly  known  as  the  doctrine  of  compensation.  Accord- 
ing to  this  view,  if  one  sense  or  mental  function  is  lacking,  in  any 
respect,  the  others  are  the  keener  to  compensate  for  the  loss.  More- 
over, based  on  the  olfactory  sense  of  the  dog,  the  visual  acuity  of 
the  hawk  and  the  superior  audition  of  certain  of  the  felines,  there 
has  arisen  the  belief  that  the  senses  degenerate  under  the  influences 
of  civilization  and  higher  culture. 

The  figures  relating  to  the  upper  limit  of  the  hearing  of  the  vari- 
ous Indian  tribes  represented  at  the  Model  Indian  School  at  the  Ex- 
position, are  given  in  tables  L,  II.,  III.  and  IV.6  The  hearing  of  71 
Indians  included  in  this  group  was  taken;  14  full-blooded  males 
and  13  of  mixed  blood;  4  full-blooded  females  and  40  of  mixed 
blood.  Of  this  number,  8  were  younger  than  sixteen  years  so  that 
data  relating  to  them  are  not  included  in  the  general  average. 
Only  6  individuals  of  the  group  were  older  than  25  years  (See 
Table  IV.)  while  but  12  of  the  63  were  older  than  20  years.  In 
other  words,  81  per  cent,  of  all  the  Indians  examined  were  between 
16  and  20  years  old.  The  average  age  of  the  entire  group  is  only 
19  years  and  2  months,  while  that  of  the  Whites  with  whom  they 
are  compared  is  23  years  and  5  months.  It  is  therefore  evident 
that,  if  the  upper  range  of  hearing  progressively  decreases  from 
earliest  childhood,  the  Indians  are  favored  in  the  comparison  with 
the  Whites.  For  the  right  ear,  the  tone  marking  the  upper  threshold 
of  hearing  of  Indians  is  on  the  average  31,975  double  vibrations  to 
the  second,  with  an  average  deviation  amounting  to  2,190  vibrations. 
The  average  for  Whites  for  the  same  ear  was  310  double  vibrations 
higher.  On  purely  statistical  grounds7  one  would  be  justified  in 

•For  general  remarks  relating  to  these  Indians  more  specifically  consult 
page  4. 

7  In  making  these  computations,  the  formulae  commonly  used  in  statistical 
data  for  measuring  the  reliability  of  a  difference  were  employed.  See  Thorn- 
dike,  "  Mental  and  Social  Measurements,"  1904,  p.  139,  et  seq. 


DATA    COLLECTED    ON    THE    UPPER   LIMIT  37 

inferring  that  the  chances  are  almost  two  to  one  (exactly  1.91  to  1) 
that  an  actual  difference  exists  between  the  upper  limit  of  hearing 
of  Whites  and  Indians  respectively.     The  difference  however  is  too 
small,  considering  that  neither  group  is  very  numerous,  to  point 
strongly  in  the  direction  of  a  real  difference.     The  age  factor,  more- 
over, is  of  some  importance  in  affecting  the  data  as  may  be  seen  when 
we  take  the  records  of  those  individuals  only  whose  ages  run  from 
16  to  20  years— the  figures  which  encompassed  the  largest  number 
of  the  Indians  examined.    We  have,  then,  51  Indians  and  43  Whites. 
When  this  reduced  group  is  taken,  the  average  upper  threshold  value 
for  Indians,  in  case  of  the  right  ear,  is  found  to  differ  only  slightly 
from  that  found  for  the  whole  group,  namely,  32,080  vibrations. 
On  the  contrary,  the  average  for  the  Whites,  when  thus  limited  to 
those  between  16  and  20  years,  is  increased  to  33,587  vibrations.     On 
statistical  grounds,  therefore,  the  chances  are  10  to  1  that  the  upper 
limit  of  hearing  for  Whites  is  1,000  vibrations  in  excess  of  that 
for  Indians,  and  400  to  1  that  a  real  difference  exists  between  the 
upper  limit  of  hearing  of  the  two  peoples,  on  the  average.     Turning 
our  attention  now  to  the  left  ear,  the  difference  between  the  two 
peoples  seems  still  greater.     The  left  ear  too  probably  gives  a  figure 
which  more  nearly  represents  the  actual  state  of  the  organs  on 
account  of  the  practise  which  the  individual  had  in  the  experiment, 
as  pointed  out  above.     For  this  ear,  on  the  average,  the  Whites  hear 
tones  of  a  pitch  amounting  to   1,500  vibrations  higher  than   do 
Indians.     Moreover,  the  probability  of  a  real  difference  between  the 
two  peoples  is  at  least  500  to  1,  which,  indeed,  is  extremely  high. 
Although  the  conclusion  is  not  so  positive  as  though  a  larger  number 
of   each  group   had  been  measured,   yet  the  data  point  in  that 
direction  to  a  degree  amounting  almost  to  certainty.     Not  only  do 
Whites  hear  tones,  which  are  more  acute,  on  the  average,  than  do 
Indians,  but  a  glance  at  the  distributions  found  in  tables  II.  and 
III.  will  show  that  the  entire  curve  for  Indians  for  both  ears  extends 
lower  than  that  of  Whites.     The  amount  of  variability  likewise  ap- 
pears to  be  greater  in  the  case  of  Indians.     As  regards  the  right 
ear,  one  white  woman  only  heard  a  tone  higher  than  any  of  the 
Indians,  and  for  the  left  ear,  the  best  Indian  did  as  well  as  any 
White. 

Again  looking  at  tables  II.  and  III.  from  another  angle,  it  may 
be  observed  that  the  relative  inferiority  of  the  range  of  Indians* 
hearing  is  not  due  to  a  few  extreme  records,  which  would  have  a 
tendency  to  distort  the  figure  representing  the  average.  As  re- 
gards the  right  ear,  the  data  presented  show  that  44  out  of  67,  or 
66  per  cent,  of  the  records  of  Indians  fall  below  the  average  for 


38 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


Whites,  and  in  case  of  the  left  ear,  41  of  the  65  records  or  63  per 
cent. 

Cocopa  Indians—  The  Sen.—  Of  this  tribe,  we  were  able  to  make 


COCOPA  INDIANS 
Highest  Audible  Tone 


Name 
Hi    . 

Skik 
Mert 


Age 

6 

14 

14 


El  Puck   15 

Jack    17 

John  Roy  18 

Joe 20 

Jerry  40 

Pablo 56 

Tom 70 

Average    32,123 

S.  D.  977 


Right  Ear 

32,180  D.V. 

31,170 

33,060 

31,170 

33,060 

31,170 

34,000 

31,170 
( 18,000 
(16,000 


Left  Ear 
30,270  D.  V. 
31,170      " 
34,000      " 

31,170  " 
31,170  " 
33,060  " 
34,000  " 
29,508  " 
(21,420  "  ) 


31,794 
1,566 


measurements  of  ten  males  only.  On  account  of  the  variations  in 
age,  too,  the  data  are  not  very  suitable  for  comparative  purposes. 
The  youngest  member  of  the  group  was  a  lad  of  six  years,  while 
the  oldest  had  passed  the  age  of  three  score  and  ten.  All  of  the 
essential  data  with  reference  to  these  people  are  presented  in  detail 
in  the  table  above.  The  records  of  the  two  oldest  men  have  been 
enclosed  in  parentheses  to  indicate  that  they  have  not  been  included 
in  casting  up  the  averages  for  the  whole.  Both  Tom  and  Jerry 
heard  even  ordinary  conversation  with  difficulty,  so  that  obviously 
their  range  of  hearing  could  not  be  taken  as  normal  to  the  group. 
Excluding,  then,  these  two  records,  it  is  seen  that  the  average  upper 
limit  of  audibility  of  Cocopa  Indians  for  the  right  and  left  ears 
respectively  is  32,123  and  31,794  vibrations  (double)  to  the  second, 
figures  which  do  not  differ  materially  from  the  averages  obtained 
from  the  more  intelligent  Indians  at  the  U.  S.  Government  schools. 
However,  considering  that  only  one  of  the  eight  individuals  whose 
hearing  records  contribute  to  the  average  was  older  than  20,  it  is 
probable  that  the  range  of  hearing  of  Cocopas  in  the  long  run 
would  be  found  to  be  less  than  that  of  the  more  intelligent  Indians; 
but  even  so,  the  difference  would  likely  be  psychological  rather  than 
organic. 

Compared  with  the  upper  limit  of  hearing  of  Whites,  the  Cocopas 
fall  significantly  lower.  Not  only  is  this  true  as  regards  the  average 
result,  but  age  for  age,  the  individual  records  are  found  to  fall 
decidedly  below  the  medians  for  Whites,  as  may  be  seen  by  com- 
paring the  distributions  of  the  groups  exhibited  in  tables  II.  and 


Name 
Bob 

Age 
40 

Sex 
Male 

Tribe 
Kwasruitl 

Right 
26  264 

Charley    
Jasper    

28 

27 

« 
u 

«( 
Nutken 

28,766 
28048 

Curley 

21 

it 

« 

26  264 

Atleo    
Ellen    

64 
35 

(( 
Female 

M 

a 

30,270 
29508 

Anna    

30 

M 

K 

28,766 

Average 

28  269 

S.  D. 

1.413 

DATA    COLLECTED    ON    THE    UPPER   LIMIT  39 

III.  In  case  of  the  upper  limit  of  hearing  for  the  right  ear,  6  of  the 
10  Cocopas  stand  lower  than  the  median  record  for  Whites  and  6  of 
the  9  in  case  of  the  left  ear. 

Vancouver  Indians— Kwaguitls  and  Nutkens.—0£  Vancouver 
Indians,  we  tested  five  males  and  two  females,  belonging  to  two 
local  tribes. 

VANCOUVER  INDIANS — KWAGUITLS  AND  NUTKENS 

Highest  Audible  Tone 

Left  Ear 
26,854  D.V. 
28,766  " 
26,854  " 
28,048  " 
28,766  " 
26,854  " 
26,854  " 
27,571  " 

852      " 

With  the  exception  of  Atleo— whose  hearing  record  is  the  best 
of  the  group— these  Indians  were  all  in  the  prime  of  life.  They  are 
Indians,  moreover,  who  have  only  to  a  small  degree  been  influenced 
by  contact  with  Whites,  inasmuch  as  their  homes  are  far  removed 
from  those  parts  where  civilization  has  made  its  march.  So  far  as 
the  data  will  permit  of  generalization,  therefore,  I  believe  these 
peoples  to  be  fairly  representative  of  the  more  intelligent  Indian 
of  North  America,  before  his  organism  has  become  modified  by  its 
adjustment  to  the  social  conditions  and  habits  of  the  invading 
Caucasians. 

In  the  case  of  both  ears,  the  degree  of  variability  among  the 
records  is  fairly  small.  By  reference  to  the  table  above,  it  is  seen 
that  the  range  of  all  the  cases  is  encompassed  by  less  than  4,000 
vibrations  to  the  second;  or  that  part  of  the  musical  scale  lying 
between  gis6  and  bis6,  i.  e.,  within  the  range  of  less  than  two  whole 
tones.  The  records  for  the  left  ear  (exhibited  in  Table  III.)  are 
lower,  as  a  whole,  but  the  difference  between  the  highest  and  lowest 
record  is  still  smaller,  being  only  about  a  semi-tone  (1912  D.  V.). 

It  is,  however,  worthy  of  note  that  not  a  single  record  of  the 
Vancouver  Indians  is  as  high  as  the  average  for  Whites.  In  fact, 
the  highest  Vancouver  Indian  record  for  the  right  ear  is  1,000  D.  V. 
lower  than  the  mean  for  Whites,  while  the  highest  for  the  left  ear 
is  3,500  D.  V.  lower.  The  numbers  are  too  small  to  apply  statistical 
methods  with  satisfaction,  but  there  certainly  is  no  question  of  the 
evident  tendency  toward  the  inferiority  of  these  Indians  in  hear- 


40  THE   HEARING   OF  PRIMITIVE   PEOPLES 

ing  range,  as  compared  with.  "Whites.  The  records  of  the  two  women 
are  poorer  than  those  of  any  of  the  men,  but  additional  representa- 
tives of  the  women  might  tend  to  reverse  this  result. 

Patagmvian  Indians— The  Tehuelche.—We  were  able  to  examine 
only  four  men  of  this  tribe,  the  data  concerning  whom  are  given 
below  in  detail.  These  Indians  represent  a  grade  of  culture  slightly 
lower  than  that  of  the  Vancouvers  just  considered;  a  tent-living 
instead  of  a  house-dwelling  people,  a  nomadic  instead  of  a  home- 
building  folk. 

PATAGONIAN  INDIANS — THE  TEHUELCHE 

Highest  Audible  Tone 

Name                                            Age                                Right  Ear  Left  Ear 

Cosimero 24                         26,854  D.  V.  26,264  D.  V.     . 

Canjo 35                         28,766      "  27,444      " 

Senchel 55          Hearing  very  defective.     About  10,000  D.  V. 

for  both  ears.  An  acuity  defect. 

Boni  Farci 18                        35,100  D.  V.  32,180  D.  V. 

Average  30,240      "  28,630      " 

S.  D 3,551      "  2,592      " 

Only  three  records  were  included  in  the  average.  The  number 
examined  is  too  small  to  draw  any  general  conclusions.  However, 
with  the  exception  of  Boni  Farci,  the  upper  limit  of  hearing  of  all 
was  found  very  much,  inferior  to  that  of  the  average  for  Whites. 
I  leave  the  data  without  further  comment. 

Indians  as  a  Whole. — From  the  foregoing,  it  is  evident  that 
whether  taken  tribe  by  tribe  or  as  a  whole,  on  the  average  as  well 
as  individually,  the  experimental  results  indicate  that  Indians  do 
not  possess  as  great  a  range  of  hearing  as  do  Whites.  If,  indeed,  we 
lump  the  records  of  all  the  Indians  irrespectively,  those  who  have 
had  the  cultural  advantages  of  the  Whites— the  tribes  represented 
in  the  group  taken  from  the  Indian  School— with  the  smaller  groups 
represented  by  Indians  closer  to  nature,  we  find  that  for  the  right 
ear,  60  of  a  total  of  83,  or  73  per  cent,  of  the  individuals  rank 
below  the  average  for  Whites,  and  64  of  82  Indians,  or  77  per  cent, 
stand  lower  than  the  average  of  Whites  as  regards  the  left  ear. 
It  is  worthy  of  note  too  that  the  better  records  were  made  by  those 
Indians  who  had  attended,  more  or  less,  the  Government  Indian 
Schools.  It  was  my  impression  also,  formed  at  the  time  of  making 
the  measurements,  that  the  better  records  were  made  by  those  indi- 
viduals who  were,  all  around,  more  intelligent  and  alert.  Un- 
fortunately, it  had  not  occurred  to  me  to  make  record  of  the  degree 
of  intelligence  of  each  person  when  tested,  although  it  might  be 
nothing  more  than  a  personal  opinion  based  upon  observation  only. 


DATA    COLLECTED    ON    THE    UPPER   LIMIT  41 

Roughly,  this  could  easily  have  been  done  with  a  fair  degree  of  ac- 
curacy, since  I  was  associated  with  and  saw  at  work  each  person  for 
the  better  part  of  an  hour.  Had  I  made  such  an  observation,  it 
would  have  enabled  me  to  determine  in  a  loose  way,  at  least,  how 
far  the  differences  in  the  upper  limit  of  hearing  between  Whites  and 
Indians  are  psychological  and  to  what  extent  organic  in  character. 
A  little  further  on,  we  shall  have  occasion  to  revert  to  this  subject 
again. 

Filipinos.— In  all,  97  Filipinos  were  tested  for  their  upper 
threshold  of  hearing.  The  data  for  four,  however,  were  so  palpably 
in  error,  that  the  records  were  rejected.  We  thus  have  93  records 
which  form  the  basis  for  the  following  study.  So  far  as  I  am  aware, 
no  statement  has  ever  been  made  with  reference  to  the  hearing  of  any 
of  the  Filipino  people,  in  any  of  its  aspects.  It  is  doubtful,  too, 
whether  so  good  an  opportunity  for  testing  these  peoples,  and  under 
circumstances  so  favorable,  will  soon  be  found  again.  If  taken  in 
the  Islands,  it  would  be  no  easy  matter  to  collect  into  a  laboratory, 
for  testing,  as  many  as  a  hundred  individuals,  representing,  as  did 
these,  almost  every  section  of  the  Philippine  Archipelago.8  We  feel 
especially  gratified  with  the  results  obtained  on  the  Filipino  peoples. 
For  the  opportunity  of  making  measurements  of  the  Filipinos,  I  am 
under  obligations  to  Major  Haskell,  IT.  S.  A.,  under  whose  orders 
the  men  came  to  the  laboratory  for  the  testing  and  without  which 
orders  it  is  doubtful  whether  the  tests  could  have  been  made  at  all. 
Obligations  are  also  due  to  Dr.  Wilson,  of  the  Philadelphia  Museum, 
who,  in  the  capacity  of  Director  of  the  Philippine  Exhibit,  used  his 
influence  in  our  behalf  to  the  extent  of  recommending  that  we  be 
given  permission  to  make  the  measurements. 

The  men  were  brought  to  the  laboratories,  four  at  a  time,  this 
number  being  tested  in  the  forenoon  and  the  same  number  imme- 
diately after  dinner.  It  may  here  be  stated  that  the  hearing  ex- 
aminations were  but  two  of  a  great  number  made  on  each  indi- 
vidual. The  men  were  ignorant  as  to  the  object  of  the  measurements 
nor  was  there  a  hint  given  of  their  purpose.  Notwithstanding,  they 
approached  the  tests  with  a  great  deal  of  interest  and  zeal,  and 
seemed  eager  to  compare  their  several  records  with  those  of  their 
fellows.  None  of  them  suspected  that  there  might  be  such  a  thing 
as  a  racial  difference  inasmuch  as  they  referred  to  my  record  as 
one,  in  all  respects,  comparable  with  one  of  theirs. 

The  men  were  taken  into  the  sound-room,  one  at  a  time,  and  the 
test  conducted  with  as  great  dispatch  as  possible  in  order  to  avoid 
the  flagging  of  interest  and  the  onset  of  fatigue. 

8  See  page  6  for  a  more  detailed  description  of  these  peoples. 


42  THE   HEARING   OF  PRIMITIVE    PEOPLES 

It  is  seen,  from  the  age  distributions  found  in  Table  IV.  (See 
p.  34)  that  4  men  were  younger  than  18  years  and  5  older  than  25. 
The  oldest  of  the  group  was  but  30.  Were  one  to  select  the  indi- 
viduals deliberately  with  the  test  of  the  upper  threshold  of  hearing 
in  view,  it  is  difficult  to  see  how  a  more  favorable  lot  could  have  been 
secured.  The  mean  age  was  21  years  and  1  month. 

Turning  now  to  tables  I.,  II.  and  III.,  it  is  seen  that  the  figure 
representing  the  upper  threshold  of  hearing  of  Filipinos  for  the 
right  ear  was  found  to  be  29,916  vibrations  to  the  second  on  the 
average,  and  for  the  left  ear  29,886  vibrations.  The  small  degree 
of  variability  found  in  the  group  is  at  once  striking.  The  average 
deviation  is  very  much  smaller  than  that  for  either  Whites  or  In- 
dians (See  Table  I.).  So  little  variability,  no  doubt,  may  be  ac- 
counted for  by  the  fact  that  the  variation  in  age  is  likewise  small 
and,  moreover,  it  may  be  noted  that  in  mental  alertness  and  general 
intelligence,  these  individuals  were  more  nearly  on  a  par  than  those 
of  any  other  group  measured,  and,  consequently,  all  mental  factors 
concerned  in  the  tests  would  become  more  largely  equalized. 

When  compared  with  Whites,  the  upper  limit  of  hearing  of  the 
Filipinos  is  decidedly  lower,  not  only  on  the  average,  but  also  as 
regards  the  general  distribution  of  the  individual  cases ;  a  fact  which 
stands  out  in  the  general  distributions  found  in  tables  II.  and 
III.  The  figures  show  that  Whites  on  the  average  have  an  upper 
limit  of  hearing  higher  by  2,369  vibrations  for  the  right  ear  and  by 
2,301  for  the  left.  On  the  basis  of  mathematical  probability,  the 
chances  are  such  as  to  amount  almost  to  an  absolute  certainty 
(10,000  to  1)  that,  even  were  the  numbers  infinitely  increased,  the 
upper  limit  of  Filipinos  would,  on  the  average,  be  lower  than  that 
of  Whites.  Indeed,  the  chances  are  about  4  to  1  (3.9  to  1)  that  the 
difference  between  the  upper  limit  of  hearing  of  Whites  and  Fili- 
pinos amounts  to  at  least  2,000  vibrations.  And,  inasmuch  as  the 
number  measured  is  sufficiently  large  to  render  the  data  susceptible 
to  fairly  accurate  statistical  treatment,  the  reliability  of  these  figures 
may  be  accepted  with  a  certain  degree  of  confidence. 

Something  of  the  standing  of  the  upper  limit  of  hearing  of  the 
Filipinos  as  a  whole  may  be  inferred  from  the  distribution  of  the 
records  as  found  in  tables  II.  and  III.  Not  only  the  mode,  but  the 
distribution  as  a  whole  is  found  to  fall  distinctly  below  that  for 
Whites.  Take,  for  example,  the  records  of  the  right  ear.  But  19 
of  the  whole  number  of  93  (about  20  per  cent.)  are  as  high  as  the 
median  record  for  Whites ;  for  the  left  ear,  only  one  Filipino  record 
is  as  good  as  the  median  for  Whites. 

In  the  data  just  presented,  were  included  the  records  of  13 


DATA  COLLECTED  ON  THE  UPPER  LIMIT 


43 


Filipino  students  attending  American  colleges  and  universities,  who 
were  temporarily  connected  with  the  Exposition  and  whom  we 
tested  as  they  chanced  to  stroll  into  the  laboratories.  These  records 
afford  an  opportunity  for  testing  to  what  extent  the  factor  of  in- 
telligence was  instrumental  in  effecting  differences  found  to  exist 
between  the  upper  limit  of  Filipinos  and  Whites.  In  mentality,  I 
take  it,  these  Filipino  students  were  on  a  par  with  the  freshmen  and 
sophomores  in  our  American  colleges  and  universities.  They 
ranked,  moreover,  in  point  of  intelligence  at  least  equal  to  the  Whites 
with  whom  the  Filipinos  are  compared  above,  inasmuch  as  the 
Whites  were  for  the  most  part  artizans  and  tradespeople,  with  a 
few  who  had  completed  college  courses.  Below  I  give  the  individual 
records  of  these  Filipino  students,  both  for  the  right  and  left  ears. 
Also  I  give  the  averages  of  the  thirteen  records  and  the  variability. 

FILIPINO  STUDENTS — MOSTLY  TAGALOGS 


Right  Ea 
31,170  D 
34,000 
31,170 
32,180 
29,508 
33,060 
30,270 
30,270 


V. 


Highest  Audible  Tone 
Left  Ear  Right  Ear 

33,060  D.V.  32,180  D.  V. 


31,170 
31,170 
32,180 
28,766 
30,270 
30,270 
28,766 


32,180 
35,100 
30,270 
33,060 

Average  31,878 
A.  D.         1,323 


Left  Ear 
32,180  D.  V. 
32,180 
33,060 
28,766 
33,060 
31,157 
1,361 


Even  these  intelligent  and  educated  Filipinos,  it  is  seen,  have 
an  upper  range  of  hearing  distinctly  lower,  on  the  average,  than 
do  Whites;  the  difference  for  the  right  and  left  ears  respectively 
being  407  and  1,930  vibrations.  Were  the  numbers  of  these  intel- 
ligent Filipinos  larger,  it  would  be  interesting  to  note  what  the  prob- 
abilities of  a  real  difference  are  between  their  upper  limit  and  that 
of  Whites.  The  data  would  incline  one  to  believe  that  they  would 
amount  to  practically  a  certainty.  It  requires  to  be  noted,  more- 
over, that  with  one  exception,  the  records  of  the  Filipino  students 
were  among  the  best  of  the  Filipinos  tested,  so  that  there  can  be  no 
doubt  but  that  the  psychological  factor  is  significant  in  accounting 
for  some  of  the  differences  discovered  between  Filipinos  and  Whites, 
though,  to  be  sure,  by  no  means  all. 

Army  officers,  who  had  done  service  for  some  time,  in  the  Philip- 
pines, and  some  teachers  who  had  spent  two  or  three  years  in  the 
Islands,  with  whom  I  conversed,  without  exception  informed  me  that 
they,  too,  had  experienced  defective  hearing  in  the  Philippines. 
But  they  attributed  this  abnormality  to  the  action  of  the  quinine, 


44  THE   HEARING   OF  PRIMITIVE   PEOPLES 

which  they  found  it  necessary  to  take  in  large  quantities,  on  account 
of  the  prevalence  of  fevers.  Since  the  natives  are  immune  to 
malaria  and  other  tropical  maladies,  and  do  not  use  quinine  or  other 
drugs  with  similar  medicinal  properties,  the  explanation  just  noted 
could  not  account  for  the  defective  hearing  of  the  Filipinos,  which, 
as  will  hereafter  be  pointed  out,  extends  not  only  to  a  diminution  of 
the  range  but  to  an  actual  lack  of  acuity  as  well.  It  would  be  in- 
teresting to  know  whether  this  is  common  to  all  dwellers  within 
tropics,  inasmuch  as  the  results  are  in  accord  with  the  data  collected 
from  the  inhabitants  of  the  Torres  Straits.* 

Amu.— Excepting  the  Vancouver  Indians,  the  Ainu  rank  lowest 
as  regards  the  upper  limit  of  hearing  of  any  of  the  peoples  I 
examined.  Owing  to  the  fewness  of  the  numbers,  it  is  impossible  to 
do  more  than  present  the  results  with  a  statement  of  their  general 
tendency,  and  perhaps  this  can  best  be  seen  from  the  comparative 
tables  II.  and  III.  It  may  be  noted  that  all  of  the  Ainu  records 
fall  lower  than  the  average  for  Whites  for  both  the  right  and  left 
ears.  The  general  tendency  seems  to  indicate  an  upper  limit  slightly 
lower  even  than  that  of  Filipinos. 

THE  AINU 

Highest  Audible  Tone 

Name                                  Age                Sex                          Right  Ear  Left  Ear 

Yazo  Osawa   23            Male                 31,170  D.  V.  31,170  D.  V. 

Kutorge  Hiramura 38               "                     30,270      "  24,754     " 

Santukuno  Hiramura  . .  53               "                     25,212      "  26,264      " 

Goro  Bete 28               "                     29,508      "  32,180      " 

Sangea  Hiramura  56  "  Less  than  10,000  D.  V.  (both  ears). 

Record  not  included  in  the  average. 

Ume  Osagwa    19            Female              28,048  D.  V.  33,060  D.  V. 

Shutratek  Hiramura    . .   33                 «                   25,212      "  26,264      " 

Kin  Hiramura 6                 "                   30,270      "  30,270      " 

Average   28,846     "  29,529     " 

A.  D 1,666      "  2,946      " 

Much  of  the  auditory  inferiority  of  the  Ainu  is  undoubtedly  to 
be  accounted  for  on  purely  psychological  grounds.  They  seemed 
an  excessively  stupid  people,  ranking  next  to  the  lowest  of  all  the 
primitive  peoples  collected  on  the  Exposition  grounds.  Their  minds 
seemed  unresponsive  and  lethargic.  They  apprehended  meanings 
poorly.  Things  once  apprehended,  moreover,  held  their  attention 
for  a  moment  only  when  they  seemed  immediately  to  relapse  into  a 
state  of  mental  indifference.  I  never  could  feel  quite  certain  that 
they  were  hearing  even  when  they  said  they  were,  inasmuch  as  in 
the  region  of  the  threshold  values  the  number  of  false  statements 
was  exceedingly  large. 

"See  Report  Cambridge  Anthropol.  Exp.,  Vol.  11. 


UN! 


DATA    COLLECTED    ON    THE    UPPER   LIMIT 


45 


The  Ainu  have  been  little  studied  and  little  is  known  of  them. 
So  far  as  I  am  aware,  no  scientific  measurements  of  them  have  ever 
before  been  made,  so  it  is  quite  unfortunate  that  more  of  the  race 
were  not  available  for  study.  It  is  a  race,  too,  which,  according  to 
travelers  and  missionaries,  is  fast  dying  out;  hence,  in  the  near 
future,  will  no  longer  be  open  to  scientific  observation. 

The  Pigmies—  Batwa,  Batsnba  and  Cheri  Cheri.—  0£  the  so-called 
Pigmies  proper,  there  were  at  the  Exposition  only  six  representa- 
tives. I  present  hearing  records  of  the  entire  number. 

THE  PIGMIES  —  BATWA,  BATSUBA  AND  CHEBI  CHERI 
Highest  Audible  Tone 


Name 
Shamba     

Age 
.  ..   30 

Tribe 
Batwa 

Eight  Ear 
31,170  D.  V. 

Left  Ear 
31,170  D.  V. 

Malinga  

...    16 

M 

37,560      " 

37,560      " 

Bushaba 

13 

1C 

32  180      " 

39,220      " 

Latuna"           .    . 

.      15 

Batsuba 

35,100      " 

35,100      " 

Otabenga  

..  .    17 

Cheri  Cheri 

30,270      " 

31,170      " 

Linn  1110               .  . 

17 

33  060      " 

30,270     " 

Average   .  .  . 

.  .   33,323      " 

34,081      " 

A.  D.   . 

2.071      " 

3,212      " 

The  records  of  the  Pigmies  are  all  high.  Were  the  same  relative 
distribution  to  continue  for  a  hundred  Pigmy  hearing  records,  they 
would  be  found  to  possess  an  upper  range  of  audition  superior  to 
that  of  any  other  people,  including  Whites.  The  general  distribu- 
tion of  their  results  stands  higher  than  that  for  Whites.  ( See  tables 
II.  and  III.)  Only  one  white  male  was  found  to  possess  a  range 
of  hearing  higher  than  that  of  any  Pigmy. 

How  shall  we  account  for  this  manifest  superiority  of  the 
Pigmy's  hearing?  Certainly  not  on  the  basis  of  a  superior  mental 
attitude  toward  the  tests,  since  the  Pigmy  ranks  low  in  the  mental 
scale— only  slightly  higher  than  the  Ainu  whom  we  have  just  con- 
sidered. Moreover,  their  interest  in  the  test  can  not  be  said  to 
have  been  especially  keen.  It  was  certainly  by  no  means  the  equal 
of  the  Filipinos  whose  upper  limit  was  found  to  be  especially  low. 
The  question  of  age  was  a  factor,  no  doubt,  since  the  Pigmies  were 
all  boys,  but  even  this  does  not  account  for  all  the  difference  found. 
Perchance,  something  of  a  relation  may  exist  between  a  high  degree 
of  sensitivity  and  extreme  motility.  The  Pigmy  is  a  motor  indi- 
vidual. Like  his  next  of  kin,  the  negro,  in  his  native  haunts,  he  is 
perpetually  on  the  move.  His  reactions  to  incoming  stimuli  likewise 
are  direct  and  excessively  overt.  Other  than  this,  there  is  certainly 
nothing  in  the  Pigmy's  environment  or  mode  of  living  which  should 
tend  to  develop  and  cultivate  any  peculiar  aptitude  in  the  way  of 
sensory  acuity,  with  which  he  seems  naturally  to  be  gifted. 


CHAPTER   V 

THE  UPPER  LIMIT  OF  HEARING  AS  AFFECTED  BY  AGE  AND  SEX 

FROM  the  data  I  was  able  to  collect  at  St.  Louis  and  some 
gathered  subsequently  from  children  in  the  public  schools,  it  was 
possible  to  select  material  which  will  throw  some  additional  light 
upon  the  relation  that  obtains  between  range  of  hearing  and  age 
and  sex.  As  regards  Whites  alone,  the  data  represents  tests  on  385 
individuals;  209  males  and  176  females,  ranging  in  age  from  5  to 
65  years. 

By  consulting  the  tables  and  charts  which  follow  (See  tables  V. 
to  XII.)  it  will  be  observed  that  the  records  of  the  individuals  have 
been  distributed  into  four-year  groups,  the  first  group  representing 
the  upper  limit  of  hearing  of  children  between  5  and  8  years  in- 
clusively; the  second  group  9  to  12  years,  and  so  on.  Beyond  49 
years,  the  numbers  tested  were  so  few  that  the  four-year  groupings 
were  dropped  and  the  records  lumped.  Such  a  procedure,  too,  is 
justifiable  on  other  grounds.  With  the  approach  of  senescence  is 
met  a  decrease  of  sensitivity,  in  general,  in  consequence  of  which 
many  of  the  data  would  bear  record  of  a  decline  in  general  sen- 
sibility rather  than  a  diminution  only  in  the  one  particular  function 
of  hearing  piercing  tones. 

In  Table  V.  the  data  are  so  arranged  as  to  contribute  informa- 
tion toward  the  significance  of  age  in  influencing  the  upper  limit  of 


TABLE   V 
HIGHEST  AUDIBLE  TONE,  ACCOBDING  TO  AGE 


White  Males  and  Females 

White  Males  and  Females 

No.  of 

Ages 

Cases 

Right  Ear. 

Left  Ear. 

Right  Ear. 

Left  Ear. 

Average 

Average 

Median 

Median 

5-8 

41 

34,826 

34,525 

34,000 

35,100 

9-12 

32 

34,614 

34,939 

35,100 

34,200 

13-16 

54 

34,418 

34,224 

34,000 

34,000 

17-20 

40 

32,466 

32,415 

32,480 

32,200 

21-24 

48 

33,491 

33,025 

32,480 

33,800 

25-28 

53 

31,557 

32,390 

32,180 

32,200 

29-32 

31 

31,464 

32,000 

32,180 

31,200 

33-36 

17 

28,816 

29,046 

28,900 

29,000 

37-40 

27 

27,512 

25,054 

26,854 

28,100 

41-44 

12 

27,953 

29,994 

29,508 

27,600 

45-48 

20 

27,382 

27,741 

26,854 

27,500 

49+ 

12 

26,020 

26,188 

28,048 

25,212 

46 


THE  UPPER  LIMIT  OF  HEARING 


47 


TABLE    VI 
HIGHEST  AUDIBLE  TONE,  ACCORDING  TO  SEX 


White  Males 

White  Females 

Ages 

No.  of 
Cases 

Right  Ear. 
Average  Vibra- 
tion Frequency 

Left  Ear. 
Average  Vibra- 
tion Frequency 

No.  of 
Cases 

Right  Ear. 
Average  Vibra- 
tion Frequency 

Left  Ear. 
Average  Vibra- 
tion Frequency 

5-  8 

18 

35,180 

34,926 

23 

34,535 

34,211 

9-12 

17 

34,500 

34,740 

15 

34,861 

35,082 

13-16 

31 

34,207 

33,893 

23 

34,671 

34,713 

17-20 

24 

32,103 

31,546 

16 

32,991 

32,849 

21-24 

26 

33,069 

31,358 

22 

33,565 

33,714 

25-28 

19 

30,834 

31,480 

34 

31,048 

32,059 

29-32 

22 

31,105 

31,761 

9 

32,740 

32,168 

33-36 

10 

29,316 

30,005 

7 

28,101 

28,161 

37-40 

15 

24,142 

26,498 

12 

25,152 

27,255 

41-44 

6 

25,316 

27,084 

6 

30,748 

31,035 

45-48 

11 

27,435 

27,894 

9 

27,319 

27,571 

49+ 

10 

25,424 

26,244 

2 

25,224 

25,826 

hearing.  In  this  table  the  sexes  have  not  been  segregated.  The 
table  is  made  to  show  differences  between  different  periods  of  life, 
both  in  terms  of  the  average  of  the  individual  records  of  each  age 
group  and  in  terms  of  the  median  or  middle  record.  The  latter 
gives  the  data  in  such  terms  that  the  influence  of  pathological,  or 
functional,  disturbances  of  hearing  is  largely  eliminated.  That  is, 
extreme  records  which  have  a  tendency  to  skew  the  average  lose 
their  unwarranted  weight.  From  this  table,  as  well  as  from  others 
which  will  follow,  something,  also,  may  be  inferred  as  to  the  rela- 
tive range  of  sensitivity  of  the  two  ears. 

In  Table  VI.  the  data  are  arranged  so  as  to  exhibit  any  sex  differ- 
ences that  might  be  found  for  the  various  age  groups.  Neither  in 
this  table  nor  Table  V.  has  there  been  worked  out,  however,  any 
measure  of  variability,  inasmuch  as  the  character  of  the  distribu- 
tions may  be  seen  in  tables  VII.  to  XII. 

Tables  VII.  to  XII.  present  the  original  data  in  such  form  that 
they  may  be  worked  over  by  anyone  who  cares  to  review  the  ques- 
tion; and,  indeed,  they  show  more  convincingly  than  any  series  of 
figures  representing  averages,  modes  or  medians  could  possibly  do, 
the  tendencies  of  the  several  groups  measured.  Perhaps  a  word  of 
explanation  is  necessary  to  an  understanding  and  interpretation  of 
these  tables.  Taking,  for  example,  Table  VII.  In  the  column  to 
the  left  are  given  the  lengths  of  the  whistle  cavity  employed  in  the 
various  hearing  measurements,  and  in  the  column  to  the  right  the 
corresponding  vibration  frequencies  (double)  of  the  resulting  tones. 
At  the  head  of  the  several  columns  are  indicated  the  different  age 
groups;  "5-8"  indicating  that  the  data  in  the  column  beneath  are 
those  secured  from  boys  and  girls  without  distinction  of  sex ;  and  so 


48 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


on  for  the  remaining  columns.  Again,  under  the  "5-8"  caption, 
the  "4"  indicates  that  four  individuals  were  measured  in  which 
the  whistle  cavity  had  a  length  of  1.4  mm.  or  the  tone  possessed  a 
vibration  frequency  of  39,220  D.  V.  (double  vibrations),  and  so  on, 
the  "12"  indicating  that  the  upper  limit  of  twelve  children  was 
marked  by  a  tone  of  35,100  D.  V. 

Extended  interpretation  and  discussion  of  the  data  contained  in 
tables  V.  to  XII.  are  uncalled  for  in  connection  with  the  problem 
of  racial  differences,  of  which  this  paper  particularly  treats.  A  few 
words,  however,  are  perhaps  not  out  of  place. 

It  will  be  observed  that  the  number  of  individual  measurements 
recorded,  especially  as  regards  the  younger  years,  is  sufficient  to 
make  the  conclusions  fairly  definite.  From  tables  V.,  VII.  and 
XII.  it  stands  out  fairly  clear  that  there  is  practically  no  shortening 
in  the  range  of  hearing  before  the  age  of  sixteen  years,  but  that- 
after  this  age  the  upper  limit  falls  slowly,  having  sunk  about  three- 

TABLE   VII 

UPPEB  LIMIT  OF  HEABINQ 
Males  and  Females   (White) — Right  Ear 


Whistle 

Ages  in 

Years 

- 

Vibra- 
lions 

Length 
mm. 

2 

w 
d 

1 

s     3 

55        3 

1 

1 

CO                l> 

•*< 
•f 

1 

18 

3° 

(Double) 
Per  Sec. 

1.2 

42,960 

1.3 

1 

40,840 

1.4 

4 

3 

3 

2 

1 

39,220 

1.5 

3 

3 

6 

3 

2 

1 

37,560 

1.6 

4 

3 

4 

3        6 

2 

1 

1 

36,360 

1.7 

12 

7 

5 

5        5 

3 

1 

35,100 

1.8 

4 

6 

15 

5        6 

5 

4 

1 

1 

34,000 

1.9 

7 

2 

7 

5        7 

8 

2 

33,060 

2.0 

6 

4 

8 

10        5 

8 

7 

2        1 

1 

32,180 

2.1 

1 

3 

4 

3        6 

6 

6 

3        2 

2 

2 

1 

31,170 

2.2 

1 

1 

3        4 

3 

3 

2        4 

1 

2 

1 

30,270 

2.3 

2 

3 

2 

2 

1 

1 

29,508 

2.4 

2        1 

1 

3 

2        2 

1 

1 

28,766 

2.5 

2        2 

5 

2        2 

3 

28,048 

2.6 

1 

27,448 

2.7 

2 

3        2 

1 

1 

26,854 

2.8 

2        1 

1 

1 

26,264 

2.9 

1 

1 

2 

25,724 

3.0 

2 

1 

1 

2 

2 

2 

25,212 

3.1 

1        2 

1 

24,754 

3.2 

1 

2 

24,196 

3.4 

1 

2 

2 

2 

23,020 

3.6 

1 

1 

1 

22,217 

3.8 

1 

1 

1 

20,973 

4.0 

1 

18,496 

<o 

-* 

00 

CO           ^ 

i> 

•<* 

CO          W 

CO 

01 

0 

Average 
D.  V? 

3? 

— 

CO 

c£ 

— 

-Tf 

•^ 

CO 

§f    if 

8 

TH" 
CO 

CO 

•*< 
»-T 

CO 

i—  1            rH 
00^          IQ^ 

<xT      t>" 

<N           <M 

& 

8 
Si 

§c 

THE    UPPER   LIMIT    OF   HEARING 


49 


TABLE   VIII 

UPPEE  LIMIT  OF  HEARING 

Males  and  Females   (White) — Left  Ear 


Whistle 

Ages  in  Years 

Vibration 

Length 

<N 

• 

0 

•* 

00                <N                «0 

3         2! 

^  * 

Fre- 

mm. 

2 

1 

3 

t^ 

s 

1                1                1 

1         1 

1       |o 

D.  V. 

1.2 

l 

42,960 

1.3 

1 

1 

40,840 

1.4 

3 

3 

i 

1 

39,220 

1.5 

5 

4 

8 

2 

2 

37,560 

1.6 

3 

3 

4 

1 

1 

1 

36,360 

1.7 

7 

6 

6 

3 

5 

2 

1          1 

1 

35,100 

1.8 

5 

5 

14 

4 

2 

1        2 

34,000 

1.9 

8 

4 

8 

3 

2 

4        3 

1          1 

33,060 

2.0 

9 

2 

4 

3 

1 

241 

1        2 

1 

32,180 

2.1 

1 

2 

4 

3 

5 

34        1 

2 

2 

31,170 

2.2 

2 

2 

2 

1 

2                 3 

1        1 

30,270 

2.3 

1 

2 

121 

1        2 

1 

29,508 

2.4 

2 

1 

1 

2        3 

28,766 

2.5 

1 

1 

112 

1 

1 

28,048 

2.6 

1 

1 

1        2 

1 

27,448 

2.7 

1 

5        1 

26,854 

2.8 

1 

1        1 

1 

26,264 

2.9 

1 

1                 1 

1 

25,724 

3.0 

1 

1 

25,212 

3.1 

1        1 

24,754 

3.2 

1        1 

2 

24,196 

3.4 

1        1 

23,020 

3.6 

1 

1        1 

22,217 

3.8 

20,973 

4.0 

2 

1 

18,496 

Average 
D.  V 

| 

iO 

3? 

| 

! 

3 

1 

S  i  1 

!  1 

3   •  28 

^     ^ 
t>r      50^ 

fourths  of  an  octave  on  the  average  by  the  forty-ninth  year.  The 
data  giving  the  median  record  for  each  age  group  disclose  the  same 
facts,  so  that  it  seems  to  matter  not  whether  we  speak  in  terms  of 
the  average  or  the  median  (See  tables  V.  to  XII.). 

It  will  be  remembered  that  Alderton,  Blake,  Galton,  Zwaarde- 
maker,  Caperius,  Myers1  and  others  found  that  by  the  age  of  12  to  13 
years,  the  upper  limit  of  hearing  already  exhibits  considerable 
shortening.  My  data  necessitate  a  conclusion  quite  at  variance 
with  that  of  these  earlier  experimenters.  Nor  can  I  suggest  an  ex- 
planation for  this  lack  of  harmony  in  our  experimental  results. 

A  mathematical  statement  of  the  probability  of  a  difference  in 
the  range  of  hearing  on  the  average  for  years  of  life  beyond  seven- 
teen, is  wholly  superfluous  in  view  of  the  distributions  of  individual 
records  exhibited  in  tables  VII.  to  XII.  which  makes  this  conclusion 
absolutely  certain.  But  to  explain  this  shortening  in  range  with 

*See  discussions  under  Chapter  II.,  page  19,  et  seq. 


50 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


increasing  years  is  a  more  serious  question.  Whether  it  is  but  a 
symptom  of  a  general  insensitivity  of  the  organism  as  the  individual 
ages  or  only  an  atrophying  of  certain  tissues  through  disuse,  which 
were  of  service  to  man  in  a  lower  stage  of  his  culture,  or  whether 
it  may  be  due  to  other  factors,  are  questions  which  await  experi- 
mental determination.  In  view  of  the  relative  inferiority  of  the 
extent  of  hearing  range  among  primitive  peoples,  the  former  of  the 
two  suggested  explanations  perhaps  seems  the  more  plausible. 


TABLE    IX 

UPPEB  LIMIT  OF  HEAEING 
Males — Right  Ear 


Whistle 
Length 
mm. 

s    2 

to 

2 

9 

S 

Ages  in  Yearn 
M         $         8 

!  I 

31! 

Vibra- 
tion Fre- 
quency 
D.  V. 

1.2 

42,960 

1.3 

40,840 

1.4 

2        1 

2 

1 

39,220 

1.5 

1        2 

4 

2 

1 

1 

37,560 

1.6 

2        2 

1 

3 

1 

36,360 

1.7 

6        4 

4 

4 

3 

1 

35,100 

1.8 

3        2 

8 

2 

3 

3 

34,000 

1.9 

4        1 

4 

4 

4 

3 

1 

33,060 

2.0 

3 

3 

6 

2 

2 

4        2 

32,180 

2.1 

1 

4 

1 

2 

3 

4        2 

2        1 

31,170 

2.2 

1 

3 

2 

2 

3        2 

2        1 

1        1 

30,270 

2.3 

1 

1 

2 

2 

1 

29,503 

2.4 

2 

1 

2 

2 

1 

28,766 

2.5 

1 

2 

3 

1 

2 

2 

28,048 

2.6 

1 

27,448 

2.7 

1 

1 

2 

1 

26,854 

2.8 

1 

1        1 

26,264 

2.9 

1 

1 

25,724 

3.0 

1 

1 

2 

2        2 

25,212 

3.1 

1 

1 

2 

1 

24,754 

3.2 

2 

24,196 

3.4 

1 

1 

2 

23,020 

3.6 

1 

1 

22,217 

3.8 

20,973 

4.0 

1 

18,496 

QO        o 

CO 

OS 

1C           CO 

N           <D 

»c       ^ 

Average 

OS             O 
rH             1C 

"f           ^ 

^T 

1 

8 

co~ 

CO 
CO 

cT 

S        « 

^"          1C* 

t>*        *o 

CO           CO 

CO 

co 

CO 

CO 

CO           S 

<M           C<J 

As  to  a  difference  in  sensitivity  between  the  two  ears,  taking 
the  results  as  a  whole,  all  ages  together,  nothing  like  a  significant 
difference  stands  out  in  the  tables  (Table  V.).  As  to  a  sex  differ- 
ence, it  would  appear  from  Table  VI.  that  woman's  range  of  hear- 
ing extends  slightly  higher  than  man's;  the  difference  is  however 
for  each  age-group  too  small  to  possess  any  high  reliability. 


THE  UPPER  LIMIT  OF  HEARING 


51 


TABLE    X 

UPPER  LIMIT  OF  HEARING 
Males   (White) — Left  Ear 


Whistle 

Ages  in  Years 

Vibra- 
tion 

Length 
mm. 

C<1 

|     2 

t3 

S8S3^f3S8g» 

Fre- 
quency 
D.  V. 

1.2 

42,960 

1.3 

40,840 

1.4 

2        1 

39,220 

1.5 

1        2 

4 

37,560 

1.6 

2        1 

2 

36,360 

1.7 

4        5 

5        1 

1         1 

35,100 

1.8 

4        4 

7 

1 

34,000 

1.9 

3        2 

5        2 

122 

33,060 

2.0 

2        1 

3        1 

112 

32,180 

2.1 

1 

2        1 

221                           2 

31,170 

2.2 

2        1 

3                                    1 

30,270 

2.3 

1 

1                           1 

29,508 

2.4 

2 

1                                                      23 

28,766 

2.5 

1                           111 

28,048 

2.6 

1        2 

27,448 

2.7 

3        1 

26,854 

2.8 

1        1 

26,264 

2.9 

1 

25,724 

3.0 

1 

25,212 

3.1 

1        1 

24,754 

3.2 

1 

24,196 

3.4 

1 

23,020 

3.6 

22,217 

3.8 

20,973 

4.0 

1 

18,496 

«o       o 

CO            <O 

OOOrHlOOO^^^ 

Average 

<M              Tt< 
OS            t^ 

CO          1C 

co^t^o^oco^ 

D.    V. 

CO           CO 

W           CO 

rH            rH            i-7           O            SO            t>.            t>.            «D 

cocococoe*e*c<ie* 

SUMMARY  AND  CONCLUSION 

Placed  in  the  order  of  superiority,  beginning  with  the  people 
whose  upper  limit  was  found  to  be  the  highest,  the  peoples  arrange 
themselves  in  the  following  order : 


Eight  Ear 

1.  Pigmies. 

2.  Whites. 

3.  Cocopa  Indians. 

4.  Indians  from  the  Schools. 

5.  Patagonian  Indians. 

6.  Filipinos. 

7.  Ainu. 

8.  Vancouver  Indians. 


Left  Ear 

1.  Pigmies. 

2.  Whites. 

3.  Cocopa  Indians. 

4.  Indians  from  the  Schools. 

5.  Filipinos. 

6.  Ainu. 

7.  Patagonians. 

8.  Vancouver  Indians. 


There  is  a  slight  difference  in  relative  order  for  the  two  ears, 
respectively,  which  may  be,  and  probably  is,  due  to  the  fact  that 


52 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


TABLE    XI 

UPPER  LIMIT  OF  HEARING 
Females   (White) — Right  Ear 


Whistle 
Length 
mm. 

2 

M 

CO 

| 

J 

Age  in  Years 

8         ^         S? 

1   1 

00              ^S 

T       §2 

i    90 

Vibration 
Fre- 
quency 

D.  v: 

1.2 

42,960 

1.3 

1 

40,840 

1.4 

2 

2 

1 

1 

1 

39,220 

1.5 

2 

1 

2 

1 

1 

•  . 

37,560 

1.6 

2 

1 

3 

3 

3 

1          1 

i 

36,360 

1.7 

6 

3 

1 

1 

2 

2 

l 

35,100 

1.8 

1 

4 

7 

3 

3 

5        1 

i 

i 

34,000 

1.9 

3 

1 

3 

1 

3 

5        1 

33,060 

2.0 

6 

1 

5 

4 

3 

6        3 

l 

i 

32,180 

2.1 

1 

2 

2 

4 

321 

2        2 

31,170 

2.2 

2 

1 

2 

i 

30,270 

2.3 

1 

3 

i 

29,508 

2.4 

1        1        2 

1 

28,766 

2.5 

1 

2                 1 

i 

28,048 

2.6 

27,448 

2.7 

1                 2 

i 

26,854 

2.8 

1 

i 

26,264 

2.9 

1 

1 

25,724 

3.0 

1 

1 

25,212 

3.1 

24,754 

3.2 

1 

24,196 

3.4 

1 

2 

23,020 

3.6 

1 

1 

22,217 

3.8 

1 

1 

20,973 

4.0 

1 

18,496 

T—  1 

TH 

10 

OO           O           i—i 

Ol            00 

OS           <O 

Average 

1 

CO 
00 

!f 

OS 

I 

CO          CO           O3 

s    g 
£   § 

CO           C<1 

sf    a 

the  numbers  making  up  some  of  the  groups  were  small.  The  larger 
groups,  Whites,  Indians  (from  schools),  and  Filipinos,  on  the  other 
hand,  retain  the  same  order,  for  the  two  ears,  unchanged.  It  is 
reasonably  certain  that  Whites  have  a  higher  upper  limit  of  hear- 
ing than  do  Indians  and  that  Indians  in  turn  have  a  wider  range 
of  tonal  hearing  than  do  Filipinos. 

The  data,  therefore,  bring  out  strikingly  and  justify  a  con- 
clusion, amounting,  practically,  to  a  certainty  that  racial  differences 
in  hearing  exist,  at  least  so  far  as  the  upper  limit  of  hearing  goes, 
and  that  the  more  cultured  people  rank  most  favorably  in  this 
respect.  So  far  as  the  data  are  comparable,  too,  my  experimental 
conclusions  with  Filipinos  are  strictly  in  accord  with  those  of  Dr. 
Myers,  on  peoples  of  the  same  race.  Dr.  Myers's  results  are  stated 
in  terms  of  the  cavity  length  of  a  small  Hawksley-Galton  Whistle 
and,  consequently,  his  data  can  not  be  compared  directly  with  my 
own,  but  Myers  found  that,  for  the  most  part,  the  Papuans  whom 


THE  UPPER  LIMIT  OF  HEARING 


53 


TABLE    XII 

UPPER  LIMIT  OF  HEARING 
Females   (White) — Left  Ear 


Whistle 
Length 
mm. 

2 

3 

o 

3 

s 

j 

S3 

^ges  in 

1 

Years 

J 

S 

1 

i  I  3  11 

Vibra- 
tion Fre- 
quency 

.2 

1 

42,960 

.3 

i 

1 

40,840 

.4 

i 

2 

1 

1 

39,220 

.5 

4 

2 

4 

2 

2 

37,560 

.6 

1 

2 

2 

1 

1 

1 

36,360 

.7 

3 

1 

1 

2 

4 

1 

111 

35,100 

.8 

1 

1 

7 

4 

2 

2 

34,000 

.9 

5 

2 

3 

1 

1 

2 

1 

1            1 

33,060 

2.0 

7 

1 

1 

2 

1 

2 

1 

121 

32,180 

2.1 

1 

1 

2 

2 

3 

3 

2 

2 

31,170 

2.2 

2 

1 

1 

2 

1 

30,270 

2.3 

2 

1 

1 

1 

11                 1 

29,508 

2.4 

1 

28,766 

2.5 

1 

1 

1 

1 

28,048 

2.6 

1 

1 

1 

27,448 

2.7 

1 

2 

26,854 

2.8 

1 

1 

26,264 

2.9 

1 

1 

1 

25,724 

3.0 

1 

25,212 

3.1 

-»-*•- 

24,754 

3.2 

1        1        1 

24,196 

3.4 

1 

23,020 

3.6 

1                 11 

22,217 

3.8 

20,973 

4.0 

2 

18,496 

rH 

a 

CO 

o» 

«* 

OS 

00 

rH 

10            10            rH            N 

Average 

rH 

cf 

1 

CO 

CO 

rH 
& 

§ 

sf 

«0 

«0 
rH 

C3           CO           C^           Cl 

he  examined,  possessed  a  rather  noticeably  shorter  range  of  hear- 
ing than  did  the  peoples  of  Scotland  in  whose  measurement  he  em- 
ployed the  same  whistle. 

Only  two  factors  in  explanation  of  the  relative  shortness  of  the 
range  of  hearing  among  primitive  peoples  have  been  suggested : 

(a)  Attention  was  called  to  the  psychological  factor  concerned 
with  the  subject's  attitude  toward  the  test,  or  the  subject's  relative 
ability  to  attend  to  stimuli.     This  mental  factor  is  undoubtedly  a 
prominent  one.     It  likewise  has  its  motor  aspects  and  relations. 
Those  individuals  who  are  relatively  more  alert,  and  whose  range 
of  motor  responses  likewise  is  greater,  were,  on  the  whole,  found 
to  possess  a  greater  range  of  auditory  sensitivity,  than  individuals 
less  given  to  motility. 

(b)  The  second  factor,  perhaps,  is  fundamentally  the  same  as 
the  first.    It  refers  to  climatic  and  geographical  influences.    It  was 
suggested  that,  perchance,  variations  in  upper  limit  of  hearing  may 


54  TEE   HEARING   OF  PRIMITIVE   PEOPLES 

be  induced  by  factors  arising  from  the  different  latitudes  in  which 
the  individuals  have  been  born  and  have  grown  up. 

Each  of  the  suggested  factors  just  enumerated,  however,  awaits 
additional  experimental  evidence  for  verification.  Unfortunately, 
I  had  neither  the  time  nor  facilities  to  enter  further  into  the  subject. 

Lastly,  it  was  found  that  age  plays  an  important  role  in  shorten- 
ing the  upper  limit  of  hearing.  While  no  perceptible  shortening 
occurs  before  the  sixteenth  year,  after  this  age  the  upper  limit 
gradually  drops,  shortening  almost  an  octave  on  the  average  during 
the  next  thirty  years. 


PART   II 

AUDITORY   ACUITY 
CHAPTER  VI 

HISTORICAL 

REFERENCE  to  the  literature  of  auditory  acuity  from  the  point  of 
view  of  this  paper  implies  its  consideration  from  two  distinct 
aspects:  (1)  the  relative  acuity  of  some  of  the  inferior  races,  and 
(2)  a  quantitative  auditory  measure.  With  reference  to  auditory 
tests  on  primitive  peoples,  the  literature  is  indeed  meager.  If  we 
exclude  haphazard  statements,  and  such  as  have  been  made  by 
tourists  without  reference  to  the  physical  and  psychological  factors 
involved,  the  classic  work  of  Dr.  Charles  Myers1  on  the  Hearing  of 
the  Murray  Islanders  is  about  all  of  consequence  that  has  found 
its  way  into  print. 

In  the  seven  volumes  which  have  been  published  relating  to 
almost  every  phase  of  the  life  and  environment  of  the  natives  of 
southern  South  America,  P.  Hyades2  and  J.  Deniker  encompass  the 
problem  of  hearing  within  a  single  paragraph.  The  statement  is 
so  abbreviated  that  I  quote  it  in  full:  "The  Fuegians  have  the 
sense  of  hearing  particularly  developed  owing  to  their  conditions  of 
life.  Yet,  by  divers  experiments  with  the  watch,  with  the  diapason, 
etc.,  we  proved  that  the  acuity  and  the  range  of  hearing,  among 
these  people  do  not  exceed  that  of  Europeans  especially  gifted  in 
this  respect.  It  was  observed  also  that  noises  such  as  are  habitually 
disagreeable  to  us  (Europeans),  an  explosion  of  a  charge  of  powder, 
or  the  hissing  of  steam  in  escaping  from  a  locomotive,  do  not  by 
any  means  produce  an  unpleasant  effect  upon  their  ears."  Such  a 
statement  as  this,  while  indicating  the  direction  of  a  tendency  in  the 
gross,  does  not  give  us  much  information  on  the  question  in  point. 
The  inference  is,  that  the  hearing  is  equal,  at  least,  to  the  average 
among  Whites.  Nothing  is  said,  moreover,  as  to  the  method  pur- 
sued in  testing,  the  individual  differences  observed,  or  of  the  number 
of  persons  tested. 

1 "  Anthropological  Expedition  to  Torres  Straits,"  Vol.  II. 

2 "  Mission  Scientifique  du  Cap  Horn,"  Tom  VII.,  p.  209.    1882-3. 

55 


56  THE   HEARING   OF  PRIMITIVE    PEOPLES 

In  keeping  with  the  statement  just  noted  are  such  observations 
as  that  of  Robertson3  who  remarks  "As  a  result  of  very  many 
observations  of  an  unscientific  kind,  I  could  never  discover  that 
Kaffirs  displayed  any  superiority  to  other  races  in  their  certainty 
of  hearing."  And  that  of  Sir  Francis  Galton4  who  says  "My  own 
experience  also,  so  far  as  it  goes,  with  Hottentots,  Damars,  and  some 
other  wild  races,  went  to  show  that  their  sense  of  discernment  was 
not  superior  to  that  of  white  men."  Giltschenko5  also  relates  that 
the  Osset,  whom  he  examined,  was  found  to  hear  the  tick  of  the 
watch  at  no  greater  distance  than  other  peoples.  However,  on  the 
open  plains  and  among  the  hills,  the  Osset  understands  spoken 
words  and  perceives  significant  sounds  at  extraordinary  distances. 
But,  as  Dr.  Myers  critically  remarks,  extraordinary  auditory  acuity 
Tinder  such  circumstances  as  that  just  related,  where  the  stimuli  pos- 
sess a  conscious  significance,  no  more  indicates  superior  hearing 
than  does  the  superior  ability  to  analyze  clangs  give  evidence  of  a 
more  efficient  organic  hearing  sensitivity. 

Myers  quotes  a  personal  communication  from  Stanley  Gardener, 
in  this  connection,  which  illustrates  what  is  patently  true  of  all 
sense  avenues,  namely:  that  even  very  intense  stimuli,  if  not  signifi- 
cant or  familiar,  are  usually  unobserved.  Gardener,  while  in  the 
Maldive  Islands,  had  an  American  clock  hanging  in  his  bungalow. 
He  observed  that  the  natives  who  had  never  seen  a  clock  would 
often  approach  within  two  yards  of  the  timepiece  without  noticing 
its  tick,  and  even  after  he  had  called  attention  to  the  sound,  they 
usually  experienced  considerable  difficulty  in  localizing  it.  Gar- 
dener further  relates  that  frequently  he  passed  behind  the  natives 
on  the  sandy  seashore,  but  that,  invariably,  they  failed  to  dis- 
tinguish his  booted  tread  from  that  of  the  bare-footed  savage. 

More  forcibly,  perhaps,  than  any  a  priori  statement  of  the  matter, 
these  observations  emphasize  the  importance  of  carefully  selected 
and  well  devised  hearing  tests  for  measuring  primitive  peoples,  such 
as  will  not  afford  undue  advantage  to  the  intelligent  over  the  in- 
ferior race  with  which  it  is  compared.  In  other  words,  if  a  com- 
parison of  hearing  is  to  be  valid,  the  stimuli  must  so  nearly  as 
possible  have  the  same  psychological  value  for  all  the  individuals  in 
question.  Unhappily,  this  condition  is  rarely  fulfilled,  not  only  as 
regards  auditory  stimuli,  but  those  affecting  other  sense  avenues  as 
well.  Whether  suitable  conditions  for  making  comparisons  obtained 
in  the  tests  of  Hyades  and  Deniker,  the  statement  of  their  conclu- 

»  "  Kaffirs  of  Hindu  Kush,"  1896,  p.  174,  quoted  from  Myers,  loc.  cit. 
*"  Inquiries  into  Human  Faculty,"  London,  1883,  p.  32. 
•Biol.  Centralb.  11:  304-318.    1891. 


AUDITORY   ACUITY— HISTORICAL  57 

sions  leaves  us  in  ignorance.  Certainly  such  statements  as  those  of 
Galton,  Robertson,  Gardener  and  Giltschenke  lose  all  their  value 
when  weighed  by  psychological  standards,  simply  because  unequal 
psychological  units  of  measure  were  employed  in  the  comparisons. 
Myers  more  nearly  meets  the  situation  than  any  of  the  above  in 
that  he  employed  a  metallic  click,  which  possesses  comparatively  few 
associations,  in  some  of  his  measurements,  while  in  others,  an  ordi- 
nary noise  produced  by  a  pith  ball  falling  upon  an  inelastic  surface 
served  as  a  stimulus.  The  last  mentioned  instrument  consisted  of 
a  telescope  tube  mounted  vertically ;  at  the  base  of  which  extended 
a  piece  of  felt,  placed  at  an  angle.  The  pith  ball  was  allowed  to 
drop  through  the  tube,  strike  the  felt  below  and  rebound,  falling 
noiselessly  upon  some  velvet  cloth  stretched  to  catch  it.  The  height 
from  which  the  pith  ball  fell  could  be  varied  so  as  to  change  the 
intensity  of  the  sounds.  This  device  was  found  unserviceable,  how- 
ever, on  account  of  surrounding  noises.  Myers  and  Rivers  found 
considerable  difficulty  in  their  work  of  measuring  the  auditory 
acuity  of  the  Murray  Islanders,  by  reason  of  extraneous  noises  which 
so  confused  the  subject  under  examination  that  he  was  frequently 
unable  to  tell  when  the  stimulus  was  present  and  when  not ;  that  is, 
whether  he  heard  the  appropriate  sound  or  not.  Later,  a  Politzer 
Hormesser  was  tried  but  with  almost  as  little  success,  though  a  cer- 
tain number  of  measurements  were  made  with  the  instrument.  But 
in  by  far  the  greater  number  of  Myers's  tests,  use  was  made  of  an 
ordinary  stop  watch,  the  acuity  of  the  native  being  recorded  by  the 
relative  distance  at  which  he  and  one  of  the  experimenters  could 
hear  the  tick.  In  each  test,  one  of  the  experimenters  stood  beside 
the  subject  and  also  listened  for  the  tick.  It  was  thus  observed 
whether  or  not  he  heard  the  tone  at  a  greater  distance  than  did 
the  native ;  the  distance  at  which  the  watch  or  the  Politzer  acuometer 
was  audible  to  the  experimenter  always  being  the  denominator  of  a 
fraction  standing  for  the  acuity  of  the  native  tested.  Thirty-five 
natives  were  tested  for  hearing.  Although  the  tests,  as  has  just  been 
indicated,  were  extremely  rough,  they  served  to  show  that  Papuans, 
on  the  whole,  do  not  hear  as  well  as  do  Europeans,  though  some  of 
the  individual  Papuans,  indeed,  heard  better  than  did  either  Myers  or 
Rivers.  On  their  return  to  England,  Myers  compared  his  own  hear- 
ing and  that  of  Rivers  with  the  hearing  of  other  Europeans  and  these 
comparisons  seemed  further  to  confirm  the  relative  inferiority  of  the 
auditory  acuity  of  the  Murray  Islanders. 

From  the  second  point  of  view  of  my  measurements  of  hearing, 
the  literature  is  voluminous.  Anything  like  a  comprehensive  review 
of  all  of  its  phases  would,  therefore,  at  once  carry  us  entirely  too 


58  THE   HEARING   OF  PRIMITIVE    PEOPLES 

far  afield.  Indeed,  it  would  be  a  bootless  task,  by  reason  of  the 
diversity  of  methods  employed  and  devices  used,  which  it  would  be 
wholly  impossible  to  place  into  any  scale  of  equivalents. 

Very  considerable  work  has  been  done  on  the  continent  of  Europe 
in  the  way  of  establishing  quantitative  auditory  measures.  Some- 
thing in  the  same  direction  has  been  accomplished  in  the  United 
States,  and  Lord  Rayleigh,  in  England,  has  pretty  thoroughly 
broken  the  ground  in  the  way  of  making  it  possible  to  determine  the 
energy  proceeding  from  certain  sonorous  sources.  I  shall  not,  at 
this  time,  attempt  to  review  the  merits  of  the  various  devices  and 
instruments  that  have  been  put  forward  for  testing  auditory  acuity. 
Few  of  these  should  concern  us  in  connection  with  a  study  of  a 
quantitative  measure  of  hearing,  inasmuch  as  they  are  at  best  only 
semi- quantitative  in  character.  The  mere  mention  of  a  few  such 
as  the  following  will  suffice  to  illustrate  the  point  in  question :  The 
Seashore  audiometer;6  Bryant's  and  Bentley V  phonograph  audiom- 
eter ;  the  audiometer  of  De  Graffe  ;8  the  audiometer  of  D  'Arsonval  ;9 
a  device  for  measuring  hearing  by  R.  Panse  ;10  an  instrument  by  W. 
De  Bechterew  j11  an  acc&umetrie  metrique  by  Tretop  ;12  an  apparatus 
for  measuring  auditory  acuity  based  on  mechanically  produced 
vowels,  by  Robin;13  etc.  Among  such  devices,  also  may  be  classified 
instruments  such  as  the  well-known  Politzer  Hormesser,  the  watch 
test,  speech  and  whisper  tests;  in  fact,  all  those  methods  and  ways 
for  testing  hearing  which  depend  on  empirically  established  norms, 
which  are  not  interchangeable  as  among  different  investigators. 
Such  devices  have  their  value  in  individual  laboratories  and  clinics, 
where  only  semi-quantitative  results  are  required  and  where  oppor- 
tunity is  afforded  for  measuring  and  establishing,  once  and  for  all, 
the  hearing  equivalent  of  the  instrument  in  use.  For  purposes  of 
investigation,  however,  they  answer  but  poorly,  in  that  it  is  never 
possible  for  other  investigators  to  review  and  verify  any  experi- 
mental conclusions  reached. 

Among  the  first  work  done  to  measure,  quantitatively,  the  in- 
tensity of  a  sound  in  objective  units— at  least  relatively  objective 
units— was  that  by  Vierordt,14  in  1878.  This  investigator  concerned 

6  University  of  Iowa  Studies,  2 :  55.    1899. 

7  Science,  19:   959.    1894. 

8  Arch.  Int.  Laryn.  15:  96. 

9  Arch.  Int.  Laryn.  15:  96. 

10  J.  of  Laryngol.  19:  534. 

11  Arch,  de  Psych.  5:   108. 

"Butt,  de  Laryng.}  Otol,  etc.  8:  20. 

13  Bull,  et  Mem.  Soc.  d'Anthropol.  3:  209.    1902. 

"Das  Mass  der  Schallstarke,  Ztsch.  f.  Biol.  14:  361.    1878. 


AUDITORY   ACUITY— HISTORICAL  59 

himself  with  the  question  of  the  relation  between  the  height  of  fall 
of  a  ball  and  the  resulting  sound  intensity.  Vierordt  believed  he 
had  established  an  experimental  formula  by  which  could  be  de- 
termined in  relative  terms  the  intensities  of  two  succeeding  sounds. 
Vierordt 's  work  was  later  reviewed  by  Oberbech,15  who  established 
experimentally  the  formula  i  =  phe  instead  of  the  formula  i  =  ph° 
which  Vierordt  had  proposed  for  expressing  the  relation  between  the 
sound  intensity  and  fall-height;  where  "c"  is  a  constant  depending 
on  the  construction  of  the  instrument,  "h"  the  height  of  fall,  "p," 
the  weight  of  the  ball  and  "i"  the  intensity  of  sound.  This  formula 
was  again  reviewed  in  Wundt's  Laboratory  in  1881  by  Tischer  who 
showed  experimentally  that  a  relation  between  the  height  of  fall 
and  the  intensity  of  the  resulting  sound  is  only  roughly  accurate 
and  such  as  to  be  impossible  of  expression  algebraically.  Further- 
more, the  relation  is  one  which  it  is  necessary  to  establish  inde- 
pendently for  every  ball  and  instrument  used.  Some  such  device, 
were  it  possible  to  state  the  relation  between  the  falling  height  and 
the  resulting  sound  intensity,  would  be  admirably  adapted  for 
auditory  testing  but,  for  the  present  at  least,  it  lies  beyond  the 
possibilities  of  a  quantitative  statement. 

The  methods  for  measuring  the  energy  of  sound  in  physical  units 
have  been  numerous.  Relatively  loud  tones  have  sometimes  been 
employed  in  determining  the  ear's  sensitivity.  By  this  method  the 
subject  is  removed  to  such  a  distance  from  the  source  of  sound  that 
it  is  just  no  longer  audible.  Then  by  calculating  the  energy  of  the 
sound  emitted,  and  knowing  the  distance  between  the  subject  and 
the  sonorous  source,  the  intensity  of  sound  at  the  ear  may  be  easily 
reckoned.  This  method  was  employed  by  Toepler  and  Boltzmann,18 
who  were  first  to  determine  the  absolute  sensitivity  of  the  human 
ear.  On  the  strength  of  Helmholtz's  generalizations,  they  calculated 
the  quantity  of  sound  energy  leaving  an  open  organ  pipe,  while 
Wolf  pursued  the  same  method  by  calculating  the  energy  going  out 
from  a  bottle  over  which  a  blast  of  air  was  made  to  pass,  giving  rise 
to  a  loud  shrill  tone.  The  method  assumes  that  all  energy  consumed 
by  the  open  organ  pipe  or  sounding  bottle  passes  over  into  aerial 
sound  wave  energy.  Knowing  the  pressure  of  the  wind  blast  play- 
ing upon  an  organ  pipe  or  bottle ;  the  quantity  of  air  consumed ;  the 
distance  between  the  subject  and  the  tone  center;  it  is  simply  a 
matter  of  arithmetic  to  determine  the  maximum  condensation  of  an 
air  wave  reaching  a  subject's  ear. 

So  far  as  I  have  been  able  to  discover,  only  two  remaining  devices 

"Wied.  Annal.  13:  254.    1881. 

18  See  Rayleigh,  "  The  Theory  of  Sound,"  1896,  Vol.  II.,  p.  433. 


60  TEE   HEARING   OF  PRIMITIVE   PEOPLES 

have  been  employed  to  arrive  at  a  quantitative  Hormass:—ihe  tun- 
ing fork  and  the  telephone.  The  tuning  fork  has  gained  promi- 
nence as  an  instrument  for  testing  hearing,  I  believe,  largely  because 
of  its  efficiency  in  a  functional  hearing  test.  For  this  purpose  it 
impresses  me  as  being  rather  a  superior  instrument.  But  it  is  well 
to  bear  in  mind  the  distinction  between  a  test's  efficiency  functionally 
and  its  psychological  value  in  testing  individual  differences.  In  a 
functional  hearing  test,  according  to  the  standards  set  by  modern 
otological  practitioners,  such  devices  are  required  as  will  measure 
hearing  efficiency  for  different  regions  of  the  tonal  scale,  and  par- 
ticularly the  ear's  relative  acuity  for  all  variations  in  pitch  found 
among  the  tones  employed  in  speech.  A  scientific  test  for  compara- 
tive hearing  acuity  on  the  contrary  concerns  itself  with  only  the  rela- 
tive sensitivity  of  individuals  as  regards  some  one  point  of  the 
hearing  scale.  A  determination  of  an  individual's  functional  hear- 
ing consequently  involves  many  problems  which  are  found  not  to 
enter  into  a  test  which  seeks  only  to  point  out  individual  differences 
in  the  sensitivity  of  the  ears  of  any  group.  Continental  European 
otologists,  however,  employ  tuning  forks  almost  altogether  both  in 
their  tests  for  general  hearing  acuity  and  for  locating  islands  of 
deafness  and  other  functional  disturbances.17 

To  Lord  Eayleigh,18  we  owe  the  credit  for  first  deriving  a 
formula  for  measuring  the  sound  energy  that  is  given  out  by  a 
tuning  fork  in  vibration.  Rayleigh's  formula  contemplates  a  micro- 
scopical measurement  of  the  amplitude  of  the  fork's  vibration.19 

"See  in  this  connection:  Bezold,  "  Functionelle  Priifung,"  1897,  S.  121; 
also  Arch,  of  Otol  25:  384.  1896;  36:  37.  1900.  M.  Paul  Robin,  "Appareil 
pour  mesurer  Pacuite"  auditive,"  Bull,  et  mem.  soc.  d'anthropol.  3:  209.  1902. 
Ostmann,  "  Zur  quantitative  Hormass,"  Arch.  f.  Anat.  u.  Physiol.  1903,  S.  321  ; 
also  by  the  same  author  Ztschr.  f.  Ohrenhk.  51:  237.  1906.  Zwaardemaker 
and  Quix,  "  Schwellenwerth  und  Tonh'ohe,"  Ztschr.  f.  Psychol.  u.  s.  w.  33  :  415. 
1903.  L.  Jacobson  and  W.  Cowl,  "  Darstellung  und  Messung  Schwingungsam- 
plituden,"  Arch.  f.  (Anat.  u.)  Physiol.  1903,  S.  1.  Many  others  might  be  men- 
tioned, but  these  are  sufficient  to  indicate  the  European  interest  in  the  tuning 
fork  as  a  measuring  instrument  of  the  ear's  hearing  power. 

18  "  Theory  of  Sound,"  Vol.  II.,  p.  437  ;  also,  "  Amplitude  of  a  Just  Audible 
Air  Wave,"  Phil.  Mag.  38  :  365.    1894. 

19  Where  "  E  "  is  the  total  energy  given  out  by  a  tuning  fork  in  motion, 
its  value  may  be  obtained  from  the  following  formula: 


Where  "I"  is  the  length,  "w"  the  width,  and  "p»  the  cross-sectional  area 
of  one  of  the  prongs  of  the  tuning  fork,  "n"  the  displacement  at  one  of  the 
vibrating  ends  of  the  prongs,  and  "  T  "  the  time  in  fractions  of  a  second,  of  a 
single  vibration. 


AUDITORY   ACUITY— HISTORICAL  61 

For  measuring  the  smallest  audible  tone  when  the  subject  is 
stationed  in  proximity  to  the  testing  instrument,  this  method  does 
not  suffice  in  that  the  displacements  of  the  ends  of  the  prongs  are  too 
small  for  microscopical  measurement.  Recently,  however,  Wien 
derived  a  formula  applicable  to  a  tuning  fork,  whereby  the  energy 
radiated,  at  any  given  moment,  may  be  stated  in  terms  of  the  time 
of  the  fork's  vibration,  if  only  the  initial  amplitude  be  known.  This 
formula  is  based  on  the  law  of  the  dampening  or  dying-out  rate  of 
tuning  forks.  The  dampening  of  a  tuning  fork  has  been  found  to 
follow  the  law,  aX  ^ht,  where  "a"  is  the  initial  amplitude,  "h" 
the  dampening  factor  and  "t"  the  time  the  fork  has  been  vibrating. 
At  any  given  moment,  therefore,  the  relation  between  the  amplitude 
of  the  fork's  vibration  for  the  experimenter  and  the  subject,  re- 
spectively, can  be  stated  by  the  formula : 

a'(Subjeet)  _,A  (.     _  e(Experimenter)), 


a2  (Experimenter) 

With  such  a  formula,  it  is  necessary,  only  once  for  all  time,  to  deter- 
mine the  dampening  factor  "h"  for  each  fork  employed,  in  order 
to  have  a  quantitative  hearing  measure  at  all  times  serviceable  for 
use. 

By  computing  the  energy  proceeding  from  a  tuning  fork,  Lord 
Rayleigh20  found  that  for  a  tone  of  512  vibrations  (double)  a  con- 
densation of  4.6  X  10"9  sufficed  to  excite  a  just  audible  tone,  in  case 
of  a  normally  hearing  subject.  According  to  Zwaardemaker21  and 
Quix,  the  quantity  of  the  energy  necessary  to  excite  a  just  audible 
tone  of  the  same  pitch  is  1.30  X  10"5  ergs.  Wead  got  the  figure 
1,100  X  10"8  ergs.  Wien  with  tuning  forks  placed  the  value  at 
612  X  10~8  ergs.  These  quantities,  it  will  be  noted,  are  small  in  the 
extreme,  and  such  as  to  baffle  all  except  the  most  delicate  and  pains- 
taking measurements. 

Work  with  the  telephone  has  been  very  meagre,  if  we  except 
some  experiments  of  a  purely  physical  sort  directed  toward  de- 
termining the  sensitivity  of  instruments  for  speech  transmitting  pur- 
poses. 

Ferrais,22  in  some  experiments  published  as  long  ago  as  1877, 
found  that  an  electrical  current  of  7  X  10~9  amperes  (528  D.  V.) 
was  sufficient  to  produce  a  sensation  of  hearing.  Preece23  found 
the  minimum  electric  current  audible  in  a  telephone  to  be 

20  Phil  Mag.  38:  365.    1894. 

^Ztschr.  f.  Psych.  33:  416.    1903. 

"Atti  della  R.  Acad.  d.  Sci.  di  Torino,  13:  1024.    1877. 

23  Brit.  Assoc.  Report,  Manchester,  1887,  p.  611. 


62  THE   HEARING   OF  PRIMITIVE    PEOPLES 

6  X  10~13  amperes.     Tait24  found  for  a  tone  of  approximately  500 
D.  V.  a  current  2  X  10"12  amperes  only  was  required  to  excite  an 
auditory  sensation  of  tone.     And  Lord  Rayleigh,25  as  a  result  o£ 
some  careful  and  extended  experiments,  placed  the  value  of  the 
minimal  current  for  a  sensation  of  hearing  in  the  telephone,   at 

7  X  10~8  amperes,  for  a  tone  of  512  D.  V.     Lord  Rayleigh  presented 
a  means  for  evaluating  the  actual  energy  given  out  by  a  telephone 
in  use.     For  a  tone  of  512  D.  V.,  the  quantity  of  energy  given  out 
by  the  telephone  for  a  tone  of  threshold  value  was  practically  that 
which  he  received  when  the  tuning  fork  was  the  auditory  excitant, 
namely,  4.6  X  10~9  ergs  per  sq.  cm.  area  at  the  opening  into  the  ear. 
Rayleigh 's  method  for  translating  the  electrical  potentials  employed 
in  producing  a  tone  of  threshold  value  into  sound  intensity  units 
is  rather  complex,  involving  some  difficult  mathematical  calculations. 
Essentially,  however,  it  consisted  in  a  measure  of  a  telephone  plate's 
amplitude  of  excursion,  from  which  was  derived  a  law  showing  the 
relation  obtaining  between  these  and  changes  in  electrical  potential. 
Although  Lord  Rayleigh  found  that  a  telephone  plate  registers  dif- 
ferences in  electrical  current  as  small  as  it  is  possible  to  measure  with 
a  galvanometer  of  more  than  ordinary  sensitivity,  and  that,  there- 
fore, the  change  in  electrical  potential  in  the  telephone  is  at  once 
a  measure  of  the  differences  in  the  intensity  of  the  sound  leaving 
such  an  instrument,  he  suggested  no  means  for  evaluating  con- 
cretely intensities  of  sounds  in  terms  of  the  excursion  of  the  tele- 
phone plate  alone.     This  work  remained  for  Max  Wien.26    Wien 
based  his  computations  on  the  assumption  that  a  telephone  plate, 
in  an  instrument  of  the  unipolar  variety,  where  the  edges  are  per- 
fectly clamped,  executes  movements  which  are  comparable  to  those 
of  circular  clamped  membranes.     Wien  derived  a  formula  whereby 
the  resulting  intensities  of  the  tones  may  be  directly  computed, 
when  the  extent  of  the  oscillations  of  the  center  of  the  telephone 
plate  is  known.     According  to  this  formula,  it  is  possible  to  express 
the  condensation  of  a  sound  wave  leaving  a  telephone,  at  any  point 
in  space,  directly  as  a  function  of  the  amplitude  of  the  plate's 
excursion  at  its  middle  point,  or  indeed,  the  same  may  be  said  of 
the  energy  of  a  sound  wave  at  any  distant  point.     The  formula,  I 
have  neither  the  inclination  nor  ability  to  verify.     But  Wien,  like 
Lord  Rayleigh,  in  the  work  of  actual  experimentation,  based  his 
computations  on  the  assumption  that  the  degree  of  electrical  poten- 

"Edin.  Proc.  9:  551.    1878. 

25 "The  Theory  of  the  Telephone"  and  "Minimum  Current  Audible  in  a 
Telephone,"  Phil.  Mag.  38:  295;  also  285.  1894. 

28 "  Die  Empfindlichkeit  des  menschlichen  Gehororgane,  Pftiiger's  Arch.  97 : 
41.  1903. 


AUDITORY   ACUITY— HISTORICAL  63 

tial  is  directly  a  measure  of  the  intensity  of  a  sound  as  it  leaves 
a  telephone.  This,  however,  seems  to  be  not  wholly  a  settled  prin- 
ciple. It  is  a  question  which  has  only  recently  again  been  opened 
in  the  psychological  laboratory  of  the  University  of  Michigan,27  so, 
perhaps,  this  may  serve  to  explain  some  of  the  unusual  results 
which  Wien  reports. 

For  a  tone  of  500  D.  V.,  Wien  obtained  a  value  in  amperes  of 
3.6  X  10'11,  as  the  current  strength  essential  to  produce  a  just 
audible  sound  in  a  telephone,  whereas,  Lord  Rayleigh  had  worked 
out  the  value  to  be  6  X  10~9  amperes.  Wien  found,  moreover,  for 
a  tone  of  pitch  3,200  D.  V.,  that  a  pressure  difference  in  the  air  wave, 
at  the  ear,  amounting  to  only  1.4  X  10'11  cms.  is  sensed  by  our 
organs  of  hearing.28 

In  some  experiments,  to  determine  roughly  the  relation  between 
the  intensity  of  tones  necessary  to  hearing  and  the  hearing  of  speech, 
Wien  29  discovered  that  even  if  the  condensation  value  of  a  sound 
necessary  to  excite  a  just  noticeable  sensation  of  hearing  had  to  be 
increased  10,000  times,  the  hearing  for  speech  is  only  slightly  inter- 
fered with.  One  of  Wien's  subjects,  who  was  hard  of  hearing,  but 
who  could  hear  loudly  spoken  words,  required  an  increase  in  the 
intensity  of  the  sound  necessary  to  just  excite  an  auditory  sensation, 
of  10,000,000  over  that  for  Wien's  own  ear  and  those  of  some  of  his 
fellow  workers  in  the  laboratory.  I  am  unable  to  criticise  Wien's 
data  in  this  regard,  on  account  of  the  many  factors  involved  in  his 
elaborate  apparatus,  which  are  not  clearly  described  in  his  published 
results.  His  figures  are,  nevertheless,  far  in  excess  of  those  which 
I  have  been  able  to  secure  with  partially  deaf  subjects,  as  will 
become  apparent  from  the  distributions  of  subjects  on  the  basis  of 
their  keenness  of  auditory  sense,  to  which  I  shall  have  occasion  to 
revert  frequently  in  the  pages  which  follow. 

27  See  "  The  Telephone  and  Attention  Waves,"  G.  L.  Jackson,  J.  of  Phil., 
Psych.,  etc.  3:  602.    1906. 

28  Professor   Webster's    "phone,"   an   elaborate   mechanism   for   generating 
tones  of  determinate  vibration  frequency  and  intensity,  also  utilizes  a  circular 
membrane  as  the  sonorous  source.     But  the  instrument,  though  possessing  com- 
mendable qualities,   is  not  adapted  for  auditory  acuity  measurements   under 
circumstances  which  make  it  necessary  for  the  subject  to  be  near  the  instru- 
ment.    See  Webster,  Boltzmann-Festschrift,  1904,  p.  866. 

29  LOG.  cit.,  p.  34. 


CHAPTER   VII 

THE  INSTRUMENT  FOR  MEASURING  AUDITORY  ACUITY 

IN  the  selection  of  a  device  for  the  measure  of  auditory  acuity, 
there  were  certain  definite  limitations  which  governed  the  choice  to 
be  made.  Almost  of  necessity,  the  tests  would  have  to  be  made  in 
buildings  and  rooms  more  or  less  open  to  the  public,  and,  if  it  be 
remembered  that  there  was  scarcely  a  room  at  the  Exposition  through" 
which  hundreds  of  people  did  not  pass  daily,  it  will  not  be  difficult 
to  apprehend  that  any  auditory  test  which  depended  upon  air  con- 
duction and  a  variation  of  the  distance  between  the  subject  and  the 
source  of  sound,  as  a  measure  of  relative  acuity,  was  at  once  removed 
from  the  realm  of  choice.  In  this  connection  it  may  be  well  to 
recollect  also  that,  to  a  large  extent,  we  were  dependent  for  subjects 
upon  these  very  conditions  which  limited  the  effectiveness  and  scope 
of  our  work — the  crowds  of  people  who  passed  through  our  rooms 
day  after  day  and  offered  themselves  as  subjects  for  experiment. 
Of  course,  this  precluded  the  possibility  of  making  measurements  in 
the  night  or,  perchance,  on  Sundays  when  there  was  a  maximum  of 
quiet  on  the  World's  Fair  Grounds.  The  strikingly  advantageous 
feature  attaching  itself  to  a  study  of  some  problem  at  a  place  where 
crowds  congregate  rests  in  the  fact  that  the  study  can  be  made 
more  extensive.  Consequently,  several  very  significant  phases  of  the 
problem  of  auditory  acuity  which  suggested  themselves  to  me  had  to 
be  neglected.  Chief  among  these  was  the  problem  of  the  relative 
acuity  of  different  races  for  significant  and  non-significant  sounds. 
This  was  very  unfortunate,  too,  it  seems  to  me,  in  that  sounds  have 
significance  for  us  largely  because  they  have  functional— social  and 
economic— values.  We  shall  never  be  able  to  state  definitely  the 
relative  standing  of  the  various  races,  with  reference  to  auditory 
acuity,  until  experimental  evidence  can  be  presented  based  on 
measures  which  have  taken  into  account  the  significance  which 
meaning  has  for  sensitivity.  Indeed,  the  barriers  cast  about  me 
were  such  as  to  restrict  the  selection  of  devices  for  measuring  the 
hearing  to  those  which  conduct  the  sound  directly  into  the  auditory 
meatus.  Thus,  it  became  a  question  of  one  of  some  three  or  four 
types  of  apparatus. 

The  first  method  suggesting  itself  is  the  one  employed  quite 
generally  by  European  continental  otologists— the  tuning  fork. 

64 


INSTRUMENT    FOR    MEASURING    AUDITORY    ACUITY  65 

A  tuning  fork  is  permanently  fixed  into  some  substantial  base,  such  as 
concrete,  marble  or  lead,  in  order  that  there  may  be  little  or  no  alteration  in 
the  time,  intensity  or  character  of  its  vibration,  the  initial  impulse  remaining 
the  same  during  the  successive  weeks  or  months  that  the  fork  may  be  used  for 
testing.  Thus  mounted,  the  fork  is  placed  in  a  sound-proof  box,  the  cover  of 
which  can  be  lifted  for  giving  the  initial  impulse  to  the  fork.  Close  to  the 
fork's  tone  center  is  fixed  a  funnel  from  the  apex  of  which  leads  a  rubber  or 
lead  pipe  which  soon  bifurcates,  allowing  an  equal  quantity  of  sound  to  pass 
into  each.  One  may  lead  to  the  subject's  ear,  and  the  other,  perchance,  to  the 
ear  of  the  experimenter.  Knowing  the  initial  amplitude  of  the  fork  and  its 
rate  of  dampening,  it  is  a  simple  matter  of  computation  to  arrive  at  a  formula 
by  which  a  subject's  auditory  acuity  can  be  reckoned  directly  from  the  length 
of  time  he  is  able  to  hear  the  sound.  Or,  having  once  for  all  determined  the 
dying  out  rate  of  any  fork  in  question,  it  is  equally  easy  to  formulate  a  rule 
for  determining  the  subject's  auditory  acuity  in  terms  of  the  lengths  of  time 
that  the  experimenter  and  the  subject,  respectively,  are  able  to  hear  a  tone  as 
it  dies  out — irrespective  of  the  fork's  initial  amplitude.  (See  p.  60  for  these 
formulae. ) 

Wherever  it  is  possible  to  be  certain  of  the  faithful  and  intelligent 
cooperation  of  a  subject  in  the  performance  of  a  test,  there  can 
be  no  question  but  that  the  tuning  fork  method  simply  and  ade- 
quately meets  all  requirements.  But  these  are  conditions  that  are 
not  often  fulfilled  even  with  adults,  much  more  rarely  so  with  chil- 
dren of  intelligent  parentage,  still  less  so  in  the  case  of  most 
children  as  they  are  found  in  the  public  schools,  and  almost  not  at 
all  in  case  of  tests  on  primitive  peoples.  The  language  difficulty  in 
communicating  to  a  subject  such  directions  as  are  essential  to  an 
understanding  of  the  modus  apemndi,  the  lack  of  interest  in  the 
procedure,  indifference  as  to  its  outcome,  fluctuation  of  the  atten- 
tion, especially  in  the  presence  of  very  faint  stimuli,  and  frequently 
willful  deceit,  all  are  factors  which  make  uncertain  results  that 
depend  on  a  subject's  statement  of  his  own  subjective  experiences. 
For  these  reasons,  not  to  speak  of  the  peculiar  perceptive  difficul- 
ties, illusory  effects,  hallucinations,  etc.,  attending  the  centering  of 
attention  on  relatively  pure  and  continuous  tones,  the  tuning  fork 
device  was  rejected. 

Some  consideration  was  also  given  to  a  phonographic  method  of 
communicating  auditory  stimuli,  first  suggested  by  Bentley.1  This 
method,  to  be  sure,  possesses  the  marked  advantage  of  allowing  the 
use  of  significant  stimuli,  such  as  spoken  numerals  instead  of  mean- 
ingless tones  or  noises.  By  the  use  of  certain  carefully  selected2 
words  possessing  vowel  and  consonant  combinations,  whose  tone 
and  intensity  values  have  been  determined,  it  might  be  possible 

1  Science,  N.  S.  19:  959.    1894. 

2  See  Andrews,  Amer.  J.  of  Psych.  15 :  26.   1904;  Wolf,  "  Ohr  und  Sprache  "; 
Bezold,  "  Functionelle  Priifung." 


66  TEE   HEARING   OF  PRIMITIVE   PEOPLES 

not  only  to  measure  the  acuity  but  the  range  of  the  ear's  function- 
ing. Difficulty,  however,  is  experienced  if  one  seeks  to  state  his 
measurements  in  quantitative  terms.  Moreover,  it  is  impossible  to 
secure  a  hard,  phonographic  record  that  will  retain  its  tonal  char- 
acter after  any  considerable  use.  Certain  individuals,  too,  experi- 
ence considerable  difficulty  in  hearing  a  phonographic  reproduction, 
as  many  do  in  understanding  conversation  over  a  telephone.  Such 
objections  to  the  use  of  a  phonograph  audiometer  as  have  just  been 
outlined,  make  its  use  for  measuring  primitive  peoples  of  question- 
able value. 

The  device  found  to  be  most  serviceable,  though  not  entirely  free 
from  objections,  was  a  form  of  the  telephone.     The  telephone  device 
was  favorably  considered,  chiefly  because  Wien  had  shown  how  the 
intensity  of  the  stimuli  transmitted  to  the  ear  from  the  telephone 
receiver  can  be  directly  and  objectively  measured.     If  such  a  con- 
summation was  within  the  range  of  probability,  it  was  hoped  to 
employ  in  the  extended  research  of  the  auditory  acuity  of  the  dif- 
ferent races  which  I  was  called  upon  to  make,  some  means  whereby 
a  definitely  quantitative  statement  might  be  made  of  the  results 
obtained.     It  is  in  this  latter  particular  that  the  classic  work  of 
Dr.  Charles  Myers  on  the  Papuans  is  defective,  together  with  prac- 
tically all  other  data  on  hearing  heretofore  published.     With  the 
use  of  the  telephone  receiver,  the  character  of  the  stimulus  I  chose 
to  employ  was  such  as  is  produced  by  the  opening  and  closing  of  an 
electric  circuit,  of  which  the  telephone  forms  a  part.     In  other 
words,  it  is  a  metallic  click  which,  to  be  sure,  is  a  sound  whose  com- 
ponents are  not  in  any  definite  harmonic  relation,  and,  consequently 
is  what  is  characterized  as  a  noise,  in  contradistinction  to  a  tone. 
Much,  notwithstanding,  may  be  said  in  favor  of  a  sound  of  such  a 
character.     In  the  first  place,  since  its  range  of  stimulation  is  large, 
it  is  more  easily  heard,  and  less  fatiguing  than  relatively  pure  tones, 
or  even  clangs  whose  tonal  elements  form  some  sort  of  a  harmonic 
series.    Noises,  too,  are  more  tangible.     They  have  more  character; 
they  possess  various  phases  and  elements  to  which  the  mind  can 
attach  itself  during  the  successive  moments  that  they  are  being  held 
in  the  focus  of  attention.     Then  too,  they  have  much  in  common 
with  spoken  language,  in  that  all  of  the  consonants  are  sounds  whose 
character  can  be  expressed  as  inharmonic.     However,  in  that  they 
are  non-significant  and  carry  no  meaning,  to  that  degree  they  are 
relatively  less  adaptable  for  general  auditory  tests.     This  is  a  condi- 
tion that  I  was  able  to  discover  no  means  of  avoiding  altogether, 
although,  to  a  certain  extent,  the  end  was  attained  by  the  manner  in 
which  the  stimuli  were  presented  to  the  subject. 


INSTRUMENT    FOR    MEASURING    AUDITORY    ACUITY 


67 


The  apparatus,  as  a  whole,  is  somewhat  of  a  departure  from 
others  which  have  been  employed  in  auditory  acuity  tests,  hence,  a 
more  or  less  detailed  description  of  its  several  parts  is  advisable. 
The  parts  of  the  apparatus  in  gross3  were  (1)  a  telephone  receiver 


connected  by  long  leads  to  the  poles  of  (2)  an  ordinary  spark  coil 
(inductorium).  The  telephone  receiver  fitted  into  one  end  of  a  long 
pasteboard  tube,  at  the  other  end  of  which  was  attached  a  cushion 
with  a  central  perforation,  against  which  the  head  and  ear  were 
•The  numerals  refer  to  the  accompanying  figure. 


68  THE   HEARING   OF  PRIMITIVE    PEOPLES 

to  rest  snugly  and  comfortably.  This  tube  measured  a  meter  in 
length  and  8  centimeters  in  diameter.  To  the  primary  poles  of  the 
induetorium  were  attached  leads  connecting  it  with  (3)  an  ordinary 
lead  accumulator  (storage  battery).  In  this  primary  circuit  were 
(4)  an  ordinary  resistance  coil;  (5)  a  "make  and  break"  device; 
(6)  a  shunt  circuit  in  which  was  placed,  (7)  a  Weston  volt-ammeter, 
and  (8)  a  switch  which  allowed  the  current  to  be  sent  through  the 
"make  and  break"  key  or  through  the  shunt  circuit  and  the  volt- 
ammeter,  as  might  be  desired.  Between  the  transmitting  device  and 
the  telephone  receiver  was  interposed  (9)  a  large  double  walled 
pasteboard  screen.  The  entire  device  ready  for  operation  is  illus- 
trated diagrammatically  in  the  figure. 

The  Induction  Coil.— For  bringing  about  changes  in  the  elec- 
trical potential  of  the  secondary  circuit,  through  the  telephone,  a 
type  of  spark  coil  was  employed  which  permitted  the  sliding  of  the 
secondary  coil  along  a  graduated  scale  farther  and  farther  from 
the  primary  coil.  The  range  of  graduation  covered  100  centimeters. 
(See  diagram.)  As  is  well  known,  by  removing  the  secondary  coil 
from  the  primary,  the  strength  of  the  current  in  the  secondary 
circuit  is  progressively  decreased.  With  a  relatively  weak  current, 
e.  g.,  with  a  voltage  of  about  2  and  amperage  of  0.5,  in  the  case 
of  my  own  ear,  the  secondary  coil  must  be  removed  from  the 
primary  on  an  average  to  a  distance  in  the  neighborhood  of  75  cm. 
before  the  click  ceases  to  me  audible.  Thus,  it  is  seen,  a  considerably 
wide  range  is  afforded  within  which  the  extremes  of  audibility  of 
any  group  may  find  a  place,  and,  obviously,  a  sufficiently  wide 
distribution  is  given  to  the  data  for  the  purpose  of  making  com- 
parisons. 

The  Storage  Battery.— It  is  a  difficult  matter  to  secure  a  type 
of  wet  or  dry  electrical  cell  which  will  give  a  perfectly  uniform 
current,  even  during  the  few  moments  that  a  hearing  test  might  be 
given.  On  this  account,  I  induced  the  Exposition  company  to 
purchase  for  me  lead  storage  batteries  (accumulators).  One  of 
these  cells  was  placed  in  the  circuit  at  a  time;  the  other,  in  the 
meantime,  being  free  for  charging.  When  charged  to  its  full 
capacity,  each  cell  possessed  an  electromotive  force  of  about  2.2 
volts.  However,  the  potential  rapidly  fell  to  about  2.0  volts, 
through  internal  leakage,  but  there  it  remained,  with  the  usage  I 
gave  the  cells,  for  several  days.  It  is  held  that  accumulators  do 
better  work  when  not  used  to  their  full  capacity.  Some  resistance 
was  therefore  always  placed  in  series  with  the  primary  induction 
coil  and  the  battery.  Almost  uniformly,  throughout  the  entire 
series  of  tests,  the  current  passing  through  "Ihe  primary  circuit 


INSTRUMENT    FOR    MEASURING    AUDITORY    ACUITY  69 

measured  0.5  amperes  and  1.9  volts.  The  current  was  measured  by 
means  of  the  Weston  volt-ammeter,  placed  in  the  shunt  circuit,  be- 
fore taking  the  measure  of  the  auditory  acuity  of  every  subject. 
The  object  of  the  long  leads  between  the  telephone  receiver  and  the 
secondary  coil,  was  to  remove  the  subject  so  far  from  the  noise  of 
"make  and  break"  key  as  could  conveniently  be  done,  within  the 
limits  of  the  sound  booth.4  Thus,  almost  any  sound  that  might  arise 
from  the  opening  and  shutting  of  the  key— the  faint  spark  or  the 
noise  attending  the  mechanical  manipulation  of  the  instrument— was 
beyond  the  hearing  of  the  subject  under  examination. 

The  "Make  and  Break"  Apparatus. — In  making  and  breaking 
an  electric  circuit  with  as  strong  a  current  as  the  one  I  employed 
in  these  measurements,  unless  particular  precautions  are  observed, 
a  spark  occurs  which  is  so  loud  as  to  be  distinctly  audible  at  a 
considerable  distance  from  the  instrument,  and  indeed  in  any  part 
of  the  sound  booth.  To  avoid  this  distracting  feature,  a  mercury 
dip  "make  and  break"  key  was  devised.  This,  in  all  essential  re- 
spects, did  not  differ  from  the  ordinary  telegrapher's  key,  except 
that  in  place  of  the  hard  contact,  a  platinum  point  was  made  to  dip 
into  a  mercury  bath  on  closing  the  circuit,  which  prevented  the 
noise  of  contact.  And,  to  prevent  a  spark,  the  surface  of  the 
mercury  was  covered  with  an  extremely  thin  coating  of  sweet  oil. 
The  whole  arrangement  was  such  as  to  be  manipulated,  generally, 
without  the  least  accompaniment  of  sound.  But  to  make  precau- 
tions doubly  certain,  a  large  screen  was  interposed  between  the 
transmitting  device  and  the  subject.  This  screen  served,  in  ad- 
dition, to  shut  off  the  subject  from  the  view  of  the  experimenter, 
making  it  impossible  for  the  latter '&  movements  to  be  seized  upon 
as  cues  to  the  character  of  the  stimuli  which  were  being  presented, 
or  for  his  presence  to  prove  a  source  of  distraction. 

Max  Wien  and  Lord  Rayleigh  had  their  subjects  hold  the  tele- 
phone receiver  snugly  against  the  ear.  By  making  the  span  between 
the  diaphragm  of  the  telephone  and  the  tympanum  of  the  ear  air 
tight,  they  believed  all  energy  given  out  by  the  vibrations  of  the 
former  would  be  transmitted  directly  into  the  ear  to  the  tympanum 
and  the  ossicles.  I  am  not  certain  that  this  method  does  not  give 
rise  to  a  molecular  transmission  of  sound  through  the  bones  of  the 
skull.  I  desired  to  avoid  bone  conduction,  if  possible,  and  there- 
fore placed,  at  the  far  end  of  the  pasteboard  tube  away  from  the 
telephone  receiver,  a  soft  leather  cushion  against  which  the  ear 
might  rest  easily  and  yet  be  shut  practically  air  tight  into  the  tube. 

*  For  a  description  of  this  sound  booth,  I  refer  the  reader  to  the  foot-note 
on  page  30. 


70  THE   HEARING   OF  PRIMITIVE   PEOPLES 

My  experience  has  been,  too,  and  that  of  those  whom  I  have  ques- 
tioned, that  when  the  ear  is  pressed  snugly  against  any  hard  surface 
or  object,  such  as  a  telephone  receiver,  small  distracting  sounds 
result  which  very  much  interfere  with  the  perception  of  faint  stimuli. 
They  give  rise,  particularly,  to  confusing  illusions  of  hearing.  This 
is  especially  true  of  those  inexperienced  in  introspection.  The 
noises  just  referred  to,  no  doubt,  are  due  to  molecular  disturbances 
arising  from  the  rubbing  of  the  head  against  the  hard  substance, 
the  tremors  of  the  hand  in  holding  the  instrument  and  no  doubt 
from  other  sources  as  well.  To  avoid  all  these  furnished  additional 
reasons  for  the  leather  cushion  and  the  removal  of  the  subject's  ear 
to  a  distance  from  the  telephone  receiver. 

The  Telephone  Receiver.— Of.  considerable  importance  in  a  test 
of  this  character  is  the  form  and  make  of  telephone  receiver  em- 
ployed. The  large  type  is  preferable  on  account  of  the  additional 
room  for  windings  on  the  solenoid ;  for  the  greater  the  number  of 
turns  of  wire  on  the  solenoid,  the  more  sensitive  is  the  instrument 
to  electrical  changes;  the  quicker  is  the  response;  and  the  more 
sensitive  is  it  to  weak  electrical  currents.  A  telephone  receiver 
with  a  single  spool  of  wire  surrounding  a  central  magnet  which 
acted  over  an  area  of  less  than  a  square  centimeter  on  the  center 
of  the  telephone  plate  was  what  I  selected.  But  in  place  of  the 
central  magnet,  I  installed  a  piece  of  extremely  soft  iron,  which 
would  retain  relatively  no  magnetism  when  not  in  use.  I  did  this, 
first,  to  avoid  the  error  due  to  changes  in  the  magnetic  character  of 
permanent  magnets  from  day  to  day,  and,  secondly,  to  do  away  with 
the  factor  of  self-inductance,  which  so  frequently  enters  as  a  dis- 
tributing element  when  telephones  are  employed  for  delicate  work. 
It  were  better  to  have  no  core  at  all,  but  the  effect  of  the  central  core 
is  to  simplify  the  character  of  the  tones  given  out  and,  consequently, 
it  can  not  safely  be  dispensed  with. 

It  has  frequently  been  observed  that  differences  in  the  tension, 
with  which  the  cap  is  turned  on  to  an  ordinary  telephone  receiver, 
decidedly  influence  both  the  intensity  and  the  character  of  the  tones 
that  are  given  out.  To  obviate  differences  in  this  respect,  I  decided 
to  fix  permanently  the  telephone  plate  to  the  instrument  I  em- 
ployed. Thus  the  distance  between  the  soft  iron  core,  or  temporary 
magnet,  and  the  diaphragm  of  the  telephone  would  remain  constant 
throughout  the  whole  series  of  tests.  In  the  instrument  as  pur- 
chased, the  plate  rested  upon  a  metallic  base,  the  cap  at  the  same 
time  serving  to  hold  the  plate  firmly  upon  its  base,  and  to  retain 
the  active  parts  within  the  hard  rubber  casing.  I  removed  the  cap 
entirely  as  it  would  be  of  no  service  in  the  testing  of  hearing,  and 


INSTRUMENT    FOR    MEASURING    AUDITORY    ACUITY  71 

fitted  over  the  diaphragm  a  small  steel  ring  which  I  fastened  firmly 
and  permanently  by  means  of  screws  to  the  metallic  frame  work  of 
the  instrument,  thus  causing  the  telephone  plate  to  retain  the  same 
position  and  tension  at  all  times. 

So  much  for  the  instrument  proper.  But  something  needs  to  be 
said  of  the  arrangements  of  the  parts  in  testing.  On  one  side  of 
the  screen  stood  the  experimenter,  with  the  induction  coil,  "make 
and  break"  key,  the  alternator,  the  ammeter-voltmeter  in  the  shunt 
circuit,  before  him— over  all  of  which  was  suspended  a  small  incan- 
descent electric  bulb  which  furnished  the  illumination.  On  the 
other  side  of  the  screen  sat  the  subject— his  head  resting  easily 
against  the  leather  cushion,  from  a  perforation  in  the  center  of 
which  the  sound  entered  the  ear  being  tested;  the  other  ear  being 
meanwhile  stopped  with  cotton. 


CHAPTER   VIII 

THE  GRADUATION  OF  THE  INSTRUMENT 

IN  this  section  a  question  will  be  considered  which  is  very  largely 
a  matter  of  physics  in  that  it  is  concerned  with  the  graduation  of  the 
telephone  apparatus  employed  in  all  my  hearing  acuity  tests.  The 
question  is  of  vital  importance.  Indeed,  the  exact  graduation  of 
the  instrument  employed  in  a  hearing  test  should  be  the  chief  con- 
cern of  an  experimenter,  and  particularly  is  this  true,  when  an 
attempt  is  made  to  state  conclusions  in  terms  of  interchangeable 
units.  Studies  of  hearing  acuity  in  which  the  telephone  method 
has  been  used,  and  in  which  there  has  been  an  attempt  to  translate 
the  auditory  acuity  of  subjects  measured  into  terms  of  physical 
units,  have  been  few  indeed.  Ferrais,1  Preece2  and  Tait3  were 
satisfied  to  record  their  conclusions  in  terms  of  the  fraction  of  an 
ampere  required  to  produce  an  auditory  sensation.  On  the  other 
hand  Rayleigh,4  Wien,5  Kempf-Hartmann6  and  Jackson7  have  trans- 
lated their  data  into  terms  of  ergs  (centimeter-gram-seconds). 
Kempf-Hartmann  and  Jackson  employed  a  reflecting  mirror  device 
for  measuring  the  excursion  of  the  telephone  plate,  a  method  which 
permitted  of  readings  down  to  an  excursion  of  0.2  mm.  only.  Wien 
and  Rayleigh  'a  writings,  therefore,  alone  are  of  interest  as  being 
historically  connected  with  that  of  mine. 

Lord  Rayleigh  reported  some  experiments  on  the  sensitivity  of 
the  telephone  as  an  instrument  for  producing  delicate  shades  of 
difference  in  the  intensity  of  tones,  while  Wien  employed  a  tele- 
phone in  his  experiments  on  the  relative  sensitivity  of  the  ear  for 
tones  of  different  pitch  values.  Lord  Rayleigh,  by  measuring  micro- 
scopically the  excursion  of  a  telephone  plate  under  varying  condi- 
tions of  electrical  current,  discovered  that  a  telephone  of  the 
unipolar  variety  is  capable  of  registering  differences  in  sound  in- 
tensity as  small  as  a  galvanometer  of  the  same  number  of  windings 
of  wire  in  the  solenoid  is  capable  of  recording.  By  inference  Lord 

*Atti  della  R.  Acad.  d.  8ci.  di  Torino,  13:  1024.    1877. 

2 Report  Brit.  Assn.   (Manchester),  1887;  611. 

*Edin.  Proc.  9:  551. 

'Phil.  Mag.  38:  285,  295.    1894. 

*Annal.  d.  Physik,  4:  456.    1901;  Pfliiger's  Arch.  97:  1.    1904. 

'Annal  d.  Physik,  8:  481.    1902. 

7  J.  of  Philos.,  Psychol.,  etc.  3:  602.    1906. 

72 


THE    GRADUATION    OF    THE   INSTRUMENT  73 

Rayleigh  concluded  that  the  current  changes  are  at  once  propor- 
tional to  the  force  of  the  resulting  sound  waves  and  that  to  measure 
the  intensity  of  a  sound  wave  leaving  a  telephone  it  is  necessary 
only  to  have  a  measure  of  the  strength  of  the  electrical  current  used 
in  generating  it.  It  was  this  extreme  sensitivity  of  the  telephone, 
which  places  it  on  a  par  with  the  galvanometer,  that  influenced  me 
to  employ  it  in  the  measurements  of  the  hearing  of  primitive  peoples. 
Wien,  after  verifying  Lord  Rayleigh 's  results  with  several  tele- 
phones, derived  a  formula  whereby  the  energy  emitted  by  a  tele- 
phone plate  in  vibration,  is  stated  in  terms  of  the  extent  of  the 
excursion  of  its  middle  point. 

In  a  hearing  test  it  is  always  desirable  to  have  the  unit  of  meas- 
urement as  accurately  defined  as  possible.  Acoustically,  the  unit 
is  defined  as  the  quantity  of  sound  energy  passing  a  square  unit 
surface  (usually  1  sq.  cm.),  perpendicular  to  the  line  of  a  sound 
wave's  progression,  in  a  unit  of  time  (1  second).  Likewise,  the 
intensity  of  a  sound  at  any  distance  from  a  sonorous  body  is  ex- 
pressed in  the  following  algebraical  formula:8 

j£=i».  a.  x  (^-  1  X^2, 


where  "E"  is  the  intensity  of  the  sound  in  ergs;  ftp"  the  density 
of  the  medium  through  which  the  sound  passes;  "a"  the  velocity  of 
sound's  propagation  in  air  at  0°  C.;  "L"  the  length  of  a  single 
sound  wave;  and  "A"  the  amplitude  of  the  sound  wave's  vibra- 
tion.9 

In  the  formula,  the  "A"  is  a  factor  whose  value  it  is  always 
difficult  to  ascertain.  Either  the  quantity  of  sound  energy  leaving 
the  sounding  body  must  be  known  or  the  degree  of  condensation  at 
some  point  distant  from  the  source  must  be  measured. 

Wien10  used  both  methods,  employing  the  latter  as  a  check  to  the 
former.  In  the  determination  of  the  value  of  "A"  at  a  distance 
from  the  source  of  sound  the  condensation  was  measured  by  observ- 
ing the  effect  of  a  sound  wave  on  a  rubber  membrane  stretched 
across  a  resonator  pitched  to  respond  to  the  tone  of  the  sounding 
source.  But  the  method  can  not  be  said  to  be  very  accurate.  It  is 
simpler  to  express  the  intensity  directly  in  terms  of  the  quantity  of 
energy  leaving  a  sonorous  center— if  this  quantity  can  be  de- 

8  Rayleigh,  "  Theory  of  Sound,"  Vol.  II.,  p.  468. 

•The  factor  indicating  the  decline  in  sound  intensity  with  distance  from 
sound  source  has  been  purposely  omitted,  for  the  reason  that  the  rate  of  decline 
is  still  an  unsettled  question.  The  best  authorities  seem  to  favor  a  decrease 
directly  as  the  distance.  See  Webster,  Boltzmann- Festschrift,  1904,  p.  866. 

"Pfliiger's  Arch.  97:  30.    1903. 


74  THE   HEARING   OF  PRIMITIVE    PEOPLES 

termined— and  to  compute  from  this  the  amount  passing  any  given 
area  at  a  point  removed  from  it. 

Instead  of  using  the  quantity  of  energy,  it  is  customary  in 
acoustics  to  express  the  force  of  a  sound  wave  in  terms  of  its  con- 
densation. For  the  convenience  of  the  reader  in  the  discussions 
which  follow,  I  shall  employ  both  figures. 

Helmholtz  established  certain  formulae,  whereby  the  intensity  of 
sound  emanating  from  circular  vibrating  membranes,  with  firmly 
clamped  edges,  can  be  calculated.  One  of  these  formulas  was 
adapted  to  a  membrane  of  the  character  of  that  found  in  a  tele- 
phone receiver  by  Wien,11  if  the  instrument  is  of  the  unipolar  type, 
in  which  event  it  is  presumed  to  emit  longitudinal  sound  waves  of 
the  sinus  variety.  The  formula  expressed  algebraically  is, 

K      (27rJV)2  x  R*  X  a 
A  =  0.147  X—.X £-3 

c1  d 

Where  " A"  represents  the  condensation;  "K"  a  constant,  the  cor- 
rection for  specific  heat;  "c"  the  rate  of  propagation  of  sound  in 
air  at  the  temperature  obtaining  when  the  measure  is  made;  "N" 
the  vibration  frequency  of  the  tone  emitted;  "R"  the  radius  of  the 
telephone  plate,  freely  vibrating;  "d"  the  distance  between  the 
telephone  and  the  ear  of  the  observer;  and  "a"  the  maximum  extent 
of  the  excursion  of  the  middle  point  of  the  telephone  plate.  Of 
these  factors,  the  value  of  "K"  may  be  computed  once  for  all  from 
the  familiar  formulae  for  temperature  corrections;12  the  values  of 
"c,"  "d,"  "N"  and  "R"  also  may  be  either  directly  measured  or 
computed,  leaving  only  the  value  of  "a"  for  various  sound  intensi- 
ties to  offer  any  serious  problem.  This  value  necessarily  must  be 
measured  independently  for  every  variation  in  the  intensity  of  tones 
employed.  The  derivation  of  the  formula  involves  some  complicated 
mathematical  deductions  which  I  shall  not  attempt  to  elaborate. 
Its  value  and  general  utility  in  a  hearing  acuity  test  where  condi- 
tions make  it  advisable  to  employ  a  telephone  for  producing  the 
auditory  stimuli,  are  obvious.  The  hearing  data  to  be  hereafter 
presented  have  been  computed  from  it.  For  purposes  of  pointing 
out  individual  differences,  however,  its  validity  is  inessential,  inas- 
much as  in  any  case  the  figure  representing  the  condensation  is 
directly  proportional  to  the  amplitude  of  excursion  of  the  middle 
point  of  the  telephone  plate. 

If,  instead  of  the  condensation,  it  is  desired  to  know  the  actual 
quantity  of  energy  passing  a  square  centimeter  area  perpendicular 

11  Loc.  tit.,  p.  46. 

"Wiillner's  "Experimental  Physik,"  Bd.  1,  s.  928.  1894;  and  Phil.  Mag. 
38:  256.  1894. 


THE    GRADUATION    OF    THE    INSTRUMENT  75 

to  the  line  of  a  sound  wave's  progression  at  any  distance  from  its 
source,  it  may  be  found  directly  from  the  figure  giving  the  con- 
densation. According  to  Lord  Rayleigh,13  the  sound  energy  passing 
a  unit  area  is  equal  to: 


Where  "p"  is  the  density  of  air  (.00129  gm.)  "at"  is  the 
velocity  of  sound  in  air  as  above,  "  A"  is  the  condensation  and  "k" 
is  a  constant  representing  the  correction  for  specific  heat. 

Conditions  were  wholly  unsuited  for  graduating  the  hearing  in- 
strument at  the  Exposition,  but  I  felt  that  no  inaccuracy  would 
result  in  case  the  graduations  were  made  at  some  subsequent  time, 
if  only  the  electrical  conditions  might  be  reproduced  to  correspond 
exactly  with  the  originals  for  each  hearing  measure  taken.  In 
making  the  original  records  of  the  hearing  acuity  of  the  different 
individuals,  therefore,  I  registered  the  data  in  terms  of  the  position 
of  the  secondary  coil  as  regards  its  distance  from  the  primary  of  an 
induction  circuit  also  making  record  at  the  same  time  of  the  char- 
acter of  the  electric  current  that  I  was  employing.  The  latter  record 
was  made  in  both  amperes  and  volts,  a  Weston  volt-ammeter  being 
used  for  the  purpose. 

The  problem  of  the  measurements  of  the  excursion  of  the  tele- 
phone plate  is  one  of  no  small  concern.  Indeed,  it  is  a  task  of  great 
difficulty  and  one  that  must  be  approached  with  patience  and  more 
than  ordinary  precision  of  method,  if  the  error  of  measurement  is 
to  be  kept  within  workable  limits.  Like  Lord  Rayleigh  and  Max 
Wien,  I  made  these  measurements  with  the  aid  of  a  compound 
microscope.  The  method  was  as  follows:  To  the  center  of  the  tele- 
phone plate  was  fixed  a  finely  drawn  out  glass  tube,  to  serve  as  an 
object  upon  which  to  focus  the  microscope.  In  order  to  clarify  the 
image  in  the  microscope,  the  tip  of  the  glass  tubing  was  first  dipped 
into  some  red  ink,  which  caused  the  red  point  to  stand  out  clearly 
in  the  field  of  view.  The  tube  was  then  attached  to  the  telephone 
plate  by  setting  it  into  a  drop  of  shellac,  which  when  dry  presents 
a  hard  and  inelastic  adhesive,  and  which  will  transmit  vibrations  in 
exactly  the  same  form  in  which  they  are  received.  At  first  an 
attempt  was  made  to  do  the  measuring  with  an  ordinary  compound 
microscope  by  mounting  the  telephone  receiver  in  such  a  way  as  to 
allow  the  glass  tubing  to  extend  horizontally  under  the  ocular  of 
the  microscope.  But  on  account  of  the  constant  vibratory  move- 
ments which  the  glass  rod  executed,  even  in  the  absence  of  an  electric 

18  "  Theory  of  Sound,"  Vol.  II.,  p.  469. 


76  THE   HEARING   OF  PRIMITIVE   PEOPLES 

current,  the  use  of  the  vertical  type  of  microscope  had  to  be  aban- 
doned. I  then  selected  a  Bosch  and  Lomb  demonstrating  microscope 
which  I  mounted  horizontally  into  a  mass  of  plaster  of  Paris,  and 
into  the  same  mass  I  mounted  the  telephone  receiver  with  the  glass 
rod  extending  downward  in  such  a  way  that  the  tip  of  the  tubing 
was  in  the  microscopic  field  of  view.  The  microscope  was  fitted 
with  a  No.  1  ocular  and  %2  objective,  which  gave  a  magnification 
varying  only  by  a  small  fraction  from  500  diameters.  The  ocular 
was  supplied  with  a  micrometer  scale,  making  it  possible  to  make 
readings  which  might  be  translated  directly  into  micromillimeters. 

Even  with  the  precautions  just  indicated,  it  was  found  that  satis- 
factory measurements  in  a  down-town  building  were  impossible, 
owing  to  the  jars  and  vibrations  arising  from  traffic  on  the  streets 
below,  which  affected  the  movements  of  the  glass  filament  mounted 
upon  the  telephone  diaphragm.  I  therefore  removed  the  entire 
apparatus  to  a  place  in  the  country,  wholly  free  from  all  external 
disturbances. 

It  had  not  occurred  to  me,  when  measuring  the  hearing  of  the 
peoples  at  the  Exposition,  that  for  the  threshold  of  hearing  of  an 
individual  with  ordinary  acuity,  an  excursion  of  the  diaphragm  of 
the  telephone  would  suffice,  which  measured  no  more  than  0.00000016 
centimeters;  a  distance,  indeed,  so  small  as  to  exceed  optical  possi- 
bilities of  measurement,  and  necessarily,  beyond  the  measuring 
capacity  of  the  most  powerful  microscopes.  This,  then,  was  a  serious 
situation.  Except  for  the  lower  acuity  values,  the  measurement  of 
the  excursion  of  the  telephone  membrane  would  be  either  wholly 
impossible  or  accurate  within  the  region  of  a  large  probable  error. 
Moreover,  when  the  limits  of  the  powers  of  the  compound  microscope 
are  exceeded,  other,  reflecting,  devices  are  even  more  useless.  A  way 
to  circumvent  this  difficulty  finally  presented  itself  to  me— what  may 
be  designated  as  a  method  of  extrapolation.  This  method  consisted 
in  making  microscopical  measurements  for  those  positions  of  the 
secondary  coil  where  it  was  possible  to  do  so  accurately  with  the 
electrical  currents  as  they  obtained  at  the  Exposition,  while  the 
hearing  records  were  being  made,  and,  for  other  positions  of  the  sec- 
ondary coil,  to  increase  the  electric  current  to  the  point  where  it 
was  possible  to  make  satisfactory  microscopic  measurements.  This 
method  was  pursued  for  every  variation  in  electric  current  that  was 
employed  in  the  hearing  tests. 

In  the  first  column  of  the  table  on  page  81,  are  tabulated  these 
measures  of  the  excursion  of  the  telephone  plate  for  the  different 
positions  of  the  secondary  coil,  when  a  current  strength  of  1.9  volt 
and  0.5  ampere  was  employed.  Under  such  conditions  of  current 


THE    GRADUATION    OF    THE   INSTRUMENT  77 

it  will  be  seen  it  was  possible  to  make  microscopic  measurements  for 
positions  of  the  secondary  coil  from  1  to  12  only,  the  figure  "1" 
here  indicating  that  the  secondary  coil  is  removed  from  the  position 
0,  or  that  in  which  the  primary  coil  is  wholly  within  the  secondary, 
by  one  centimeter.  The  position  10  indicates  that  the  secondary 
coil  is  removed  by  10  centimeters  from  the  zero  position,  and  so  on. 
Beyond  the  reading  12,  the  diaphragm  excursions  were  so  small  that 
they  could  not  be  accurately  evaluated  from  the  readings  on  the 
micrometer  scale.  In  point  of  fact  for  the  position  12  the  excursion 
amounted  to  0.000045  centimeter  only,  which  extended  over  only 
about  one  fifth  of  a  single  space  on  the  micrometer  scale  of  the 
eye-piece  of  the  microscope,  and  is  about  as  small  as  can  be  measured 
with  much  certainty. 

Each  figure  given  in  the  table  is  the  average  of  at  least  five  inde- 
pendent readings.  Frequently,  too  wide  discrepancies  appeared  in 
the  separate  readings,  in  which  event  the  measurements  were  re- 
peated until  a  certain  degree  of  harmony  was  found  among  them. 
It  is  unnecessary  to  give  in  detail  the  several  individual  measure- 
ments from  which  the  averages  given  in  the  table  were  made,  and 
inasmuch  as  some  twenty  different  strengths  of  electrical  current 
were  used  in  the  original  hearing  records,  the  tabulations  of  all 
would  alone  cover  too  many  pages.  The  inconstancy  in  electrical 
current  arose  from  the  fact  that  it  was  impossible  to  keep  the  storage 
batteries,  which  supplied  the  current,  up  to  full  strength  from  day 
to  day.  No  inaccuracy,  however,  need  result  from  this  except  that 
which  might  be  occasioned  by  certain  errors  of  observation  in  dif- 
ferent microscopical  measurements,  which  need  not,  in  any  case, 
exceed  10  per  cent.,  as  will  appear  from  the  data  which  will  shortly 
be  presented.  Only  a  very  few  of  the  hearing  records  taken  were 
found  to  be  so  poor  that  a  current  intensity  of  such  strength  was 
required  as  that  represented  by  the  8  or  10  position  of  the  secondary 
coil  in  the  induction  circuit.  Since  the  excursion  of  the  center  of 
the  telephone  plate  for  positions  of  the  secondary  coil  further  re- 
moved than  12  could  not  be  measured  directly  under  normal  current 
conditions  as  they  obtained  at  the  Exposition  (T  =  1.9;  A  =  0.5), 
the  value  of  the  excursion  for  these  subsequent  positions  had  to  be 
derived  indirectly,  as  suggested  above. 

First,  I  increased  the  intensity  of  the  current  in  the  primary 
circuit 'to  a  voltage  of  10.0  and  an  amperage  of  0.5;  and  repeated 
the  measurements  as  before.  This  stronger  electrical  current  was 
drawn  from  the  main  of  an  electric  light  conduit,  resistance  in  the 
shape  of  incandescent  lamps  being  placed  in  series  with  this  circuit 
to  reduce  it  to  the  required  strength.  With  a  current  of  this  in- 


78  THE   HEARING   OF  PRIMITIVE   PEOPLES 

tensity,  it  was  possible  to  continue  the  measurements  until  the  sec- 
ondary coil  reached  the  position  19.  It  was  found  that  the  excur- 
sions of  the  telephone  plate  for  a  current  strength  of  10  volts  were 
approximately  seven  times  (6.72)  those  when  the  voltage  was  1.9. 
The  readings  for  this  current  intensity  are  to  be  found  in  the  second 
column  of  the  table  on  page  81.  If  now  the  microscopical  readings 
of  the  excursion  of  the  middle  part  of  the  telephone  plate  for  this 
strength  of  the  electrical  current  (10  volts)  is  divided  by  this  figure 
(6.72)  the  readings  should  correspond  with  those  obtained  from  the 
weaker  current.  It  is  significant  that  in  no  case  does  a  result  so 
obtained  differ  by  more  than  10  per  cent,  from  its  corresponding  one 
to  be  found  in  the  first  column.  This  indicates  that  the  method 
gives  results  which  are  accurate,  at  least,  to  within  10  per  cent. 
With  this  stronger  current,  for  the  first  position  of  the  secondary 
coil,  the  oscillations  of  the  glass  tip  were  so  violent  as  to  extend  too 
far  beyond  the  micrometer  scale  of  the  ocular  to  be  read.  Beyond 
the  position,  19,  the  extent  of  excursion  on  the  contrary  was  again 
too  small  for  measurement.  For  positions  beyond  this  point  the 
strength  of  the  electrical  current  had  again  to  be  increased;  the 
current  in  the  primary  circuit  being  raised  to  a  voltage  of  107  and 
an  amperage  of  1.1.  This  was  about  as  powerful  a  current  as  I 
felt  justified  in  sending  through  a  wire  of  the  dimensions  of  that 
with  which  my  primary  coil  was  wound,  owing  to  the  danger  of 
burning  off  the  insulations.  The  microscopic  readings  with  this  cur- 
rent intensity  are  to  be  found  in  column  three  of  the  table  on  page 
81.  Excursions  of  the  telephone  plate  corresponding  to  positions 
of  the  secondary  coil  nearer  than  12,  it  was  again  impossible  to 
measure,  inasmuch  as  the  extent  of  its  oscillations  exceeded  the 
limits  of  the  micrometer  scale.  At  the  other  end,  microscopic  meas- 
urements were  possible  to  the  position  of  64  of  the  secondary  coil, 
that  is,  until  the  secondary  was  removed  from  the  primary  coil  to  a 
distance  of  64  centimeters.  There  remained  about  twenty-one  of 
the  hearing  records  of  whites  and  one  of  Indians  in  which  the  sec- 
ondary coil  was  beyond  this  point.  The  excursions  for  the  remain- 
ing positions  of  the  secondary  coil,  therefore,  had  to  be  gotten  by 
some  other  method.  Two  suggested  themselves. 

The  first  of  these  subsidiary  methods  was  based  on  the  experi- 
mental conclusions  reached  by  Lord  Rayleigh14  and  Wien15  to  the 
effect  that  a  telephone  is  as  sensitive  to  changes  in  electrical  poten- 
tial as  an  ordinary  galvanometer  is  capable  of  measuring,  especially 
as  regards  small  currents.  In  keeping  with  this  method,  I  selected 

"Phil.  Mag.  38:  287.    1894. 
"Pfliiger's  Arch.  97:   11.    1903. 


THE    GRADUATION    OF    THE    INSTRUMENT  79 

ten  intelligent  subjects— boys  12  to  14  years  old— for  whom  I 
determined  the  average  current  intensity  necessary  to  produce  a  tone 
of  threshold  value  for  all  positions  of  the  secondary  coil  from  10  to 
75  centimeters  removed  from  the  primary.  If,  according  to  Lord 
Rayleigh,16  the  excursion  of  the  middle  point  of  the  telephone  plate 
is  directly  proportional  to  the  electromotive  force,  the  excursion  of 
the  telephone  plate  for  positions  of  the  secondary  coil  where  micro- 
scopical measurements  are  impossible  may  be  computed. 

In  detail,  the  mode  of  procedure  was  as  follows:  The  secondary 
coil  was  placed  10  centimeters  removed  from  the  zero  position  and 
the  current  passing  through  the  primary  circuit  uniformly  without 
resistance  (V  =  5.0;  A  =  0.5)  was  reduced  by  placing  resistance  in 
the  circuit  until  the  threshold  of  hearing  was  reached  for  each  of 
the  subjects.  A  record  was  then  made  of  the  number  of  ohms  of 
resistance  required.17  Then,  in  order,  the  same  procedure  was  fol- 
lowed for  other  positions  of  the  secondary  coil  up  to  75.  It  seems 
scarcely  necessary  to  present  all  these  data  in  detail.  In  point  of 
fact,  the  method  was  not  extremely  accurate,  due  no  doubt  in  a 
large  measure  to  variations  in  the  attentive  capacity  of  my  youthful 
subjects  from  moment  to  moment,  hour  to  hour,  and  from  day  to 
day.  In  general,  however,  the  data  secured  were  such  as  to  justify 
a  favorable  conviction  relative  to  the  accuracy  of  the  main  method 
employed,  for  while  the  variations  between  the  two  methods  were 
considerable,  the  figures  gotten  from  the  latter  method  followed  along 
the  same  line  as  those  from  the  first. 

The  second  subsidiary  method  was  based  on  the  assumption  that 
the  law  of  the  decrease  of  the  intensity  in  the  secondary  circuit  of 
an  induction  coil  holds  uniformly,  as  the  two  circuits  are  separated 
more  and  more  widely.  That  is,  by  determining  the  ratios  of  the 
excursion  of  the  telephone  plate  for  the  several  positions  of  the 
secondary  coil  nearer  to  the  primary  than  64  centimeters,  and  thus 
determining  the  rate  of  the  fall,  it  was  assumed  that  with  a  method 
of  extrapolation  the  excursion  of  the  telephone  plate  for  positions 
of  the  secondary  coil  farther  removed  from  the  primary  than  64 
centimeters  could  be  calculated  with  a  fair  degree  of  accuracy.18 

If  we  take  the  telephone  excursions  as  they  appear  in  the  third 
column  of  the  table  on  page  81,  where  the  strongest  electrical  poten- 
tial prevailed,  and  divide  the  excursion  of  the  telephone  plate  for 

MLoc.  cit.,  p.  287. 

17  The  resistance  coils  used  were  those  of  a  standardized  box,  kindly  loaned 
to  me  from  one  of  the  physical  laboratories. 

18  For  positions  of  the  secondary  coil   16  and  beyond,  the  primary  was 
wholly  outside  the  secondary  coil,  and  consequently  it  would  be  unreasonable 
to  believe  that  there  would  be  any  change  in  the  law  of  fall  for  these  positions. 


80 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


the  position  of  the  secondary  coil,  44,  by  that  for  the  position  42, 
and  that  for  the  position  46  by  the  excursion  for  the  position  44, 
etc.,  until  the  last  measurable  position  64  is  reached,  the  general 
fractional  rate  of  decline  in  excursion  is  found.  I  present  the  sepa- 
rate figures: 


.00012  /.00013  0.93 

.00011  /.00012  0.92 

.000096/.00011  0.87 

.000086/.000096  0.91 

.000079/.000086  0.92 

.000069/.000079  0.87 


.000064/.000069   0.93 

.000058/.000064   0.91 

.000052/.000058   0.90 

.000049/.000052   0.94 

.000045/.000049   0.92 

Average  rate  of  decline  . .  0.91 


As  stated  above,  if  it  is  assumed  that  the  rate  of  decline  for  the 
last  five  positions  of  the  secondary  coil  is  the  same  as  for  the  eleven 
just  preceding  as  indicated  in  the  data  given,  it  becomes  necessary 
only  to  multiply  the  excursion  0.000045  centimeter  of  the  64  position 
by  0.91  to  have  the  excursion  for  the  position  66,  and  hence  the 
excursion  of  the  telephone  plate  for  this  position  would  be  0.000041 
centimeter  under  the  conditions  of  current  as  they  obtained  in  the 
readings  of  the  third  column.  Multiplying  0.000041  centimeter  by 
0.91  we  get  0.000037  centimeter  as  the  excursion  of  the  telephone 
plate  for  the  position  68.  Continuing  the  same  process,  the  excur- 
sion for  position  70  is  0.000034  centimeter;  for  position  72,  0.000032 
centimeter,  and  for  position  75,  allowing  for  the  increase  in  interval, 
0.000028  centimeter. 

It  may  be  noticed  that  for  the  positions  of  the  secondary  coil 
removed,  respectively,  10,  11  and  12  centimeters  from  the  primary, 
microscopic  readings  were  secured  for  three  different  current  intensi- 
ties. The  figures  given  in  the  table  for  each  of  these  positions  of 
the  secondary  coil,  moreover,  are  the  averages  of  at  least  10  inde- 
pendent microscopical  readings.  Especial  care  was  observed  at 
these  positions  in  order  to  afford  an  accurate  basis  for  determining 
the  ratio  of  excursion  of  the  telephone  plate  for  the  three  intensities 
of  electrical  current  used.  In  Series  II.,  where  the  voltage  was  10, 
amperage  0.5,  the  excursion  of  the  telephone  plate  on  the  average 
was  6.72  times  as  large  as  in  Series  I.,  where  the  voltage  was  1.9, 
amperage  0.5,  and  in  Series  III.,  where  the  voltage  was  107,  am- 
perage 1.1,  an  excursion  on  the  average  resulted  which  was  about 
27.8  times  as  large  as  in  Series  II.,  and  just  about  187  times  as  large 
an  excursion  as  in  Series  I.  When  allowance  is  made  at  these  posi- 
tions (10,  11  and  12)  for  differences  in  current  strength,  that  is,  in 
case  the  telephone  plate's  excursion  for  positions  10,  11  and  12  of 


THE    GRADUATION    OF    THE    INSTRUMENT 


81 


TABLE    XIII 
EXCURSIONS  OF  THE  TELEPHONE  PLATE  FOB  DIFFERENT  CURRENT  STRENGTHS 


Position 

Current 

Current 

Current 

Position 

Current 

Position 

Current 

of  the 
Secondary 
Coil 

Strength 
Amp.=0.5 
Volt.  =1.9 

Strength 
Amp.=0.5 
Volt.  =10.0 

Strength 
Amp.=l.l 
Volt.  -107.0 

of  the 
Secondary 
Coil 

Strength 
Amp.=l.l 
Volt.  =107.0 

of  the 
Secondary 
Coil 

Strength 
Amp.=l.l 
Volt.=107.0 

cms. 

cms. 

cms. 

cms. 

cms. 

1 

21 

0.0011 

54 

0.000069 

2 

0.06 

22 

0.00092 

56 

0.000064 

3 

0.011 

0.079 

23 

0.00077 

58 

0.000058 

4 

0.0036 

0.023 

24 

0.00064 

60 

0.000052 

5 

0.0015 

0.009 

25 

0.00052 

62 

0.000049 

6 

0.00072 

0.005 

26 

0.00049 

64 

0.000045 

7 

0.00032 

0.0024 

27 

0.00037 

66 

0.000041 

8 

0.00023 

0.0014 

28 

0.00034 

68 

0.000037 

9 

0.00015 

0.0013 

30 

0.00030 

70 

0.000034 

10 

0.000093 

0.00061 

0.016 

32 

0.00024 

72 

0.000032 

11 

0.000064 

0.00045 

0.013 

34 

0.00021 

75 

0.000028 

12 

0.000045 

0.00028 

0.0081 

36 

0.00019 

13 

0.00023 

0.0067 

38 

0.00017 

14 

0.00019 

0.005 

40 

0.00015 

15 

0.00015 

0.0043 

42 

0.00013 

16 

0.00011 

0.0034 

44 

0.00012 

17 

0.000094 

0.0029 

46 

0.00011 

18 

0.000073 

0.0021 

48 

0.000096 

19 

0.000063 

0.0017 

50 

0.000086 

20 

0.0014 

52 

0.000079 

the  secondary  coil,  in  Series  II.  are  divided  by  6.72  and  in  Series  III. 
by  187,  the  results  appear  as  in  the  following  summary : 


TELEPHONE  PLATE'S  EXCURSION 


Position  of 
the  Secondary 
Coil 

Series  I 

Series  II/6.72 

Greater  or  less 
than  in 
Series  I 

Series  HI/187 

Greater  or  less 
than  in 
Series  I 

10 
11 
12 

0.000093  cm. 
0.000064    " 
0.000045    " 

0.000094cm. 
0.000068   " 
0.000042    " 

1.0  per  cent. 
6.2      " 
6.7       " 

0.000085cm. 
0.000069  " 
0.000043  " 

8.  7  per  cent. 
7.8       " 
4.5      " 

Average  difference  between  series  4.6       " 

7.0      " 

Series  II.  and  III.  have  10  readings  in  common,  for  positions  of 
the  secondary  coil  from  10  to  19.  Comparing  Series  II.  with  Series 
III.,  that  is,  by  dividing  the  excursions  of  the  telephone  plate  in 
Series  III.  for  positions  10,  11  and  12,  to  19  of  the  secondary  coil 
by  27.8,  we  get  the  results  in  the  summary  below. 

From  the  data  just  exhibited,  it  is  possible  to  determine  what 
degree  of  accuracy  may  be  looked  for  with  reference  to  the  method 
of  extrapolation  here  employed.  It  is  seen  that  the  average  differ- 
ence in  result  between  the  microscopical  measurements  of  the  tele- 
phone plate  with  the  electrical  current  as  it  obtained  at  the  Exposi- 
tion (voltage  1.9;  amperage  0.5)  and  the  next  stronger  current 


82 


THE   HEARING   OF  PRIMITIVE   PEOPLES 
TELEPHONE  PLATE'S  EXCURSION 


Position  of  the 
Secondary  Coil 

Series  II 

Series  III/27.8 

Greater  or  less  than 
Series  II 

10 

0.00061    cm. 

0.00058   cm. 

5.0  per  cent. 

11 

0.00046 

0.00046 

2.2       " 

12 

0.00028 

0.00029 

3.6       " 

13 

0.00023 

0.00024 

4.4      " 

14 

0.00019 

0.00018 

5.3      " 

15 

0.00015 

0.00015 

0.0      " 

16 

0.00011 

0.00012 

9.1       " 

17 

0.00094    " 

0.00010 

6.4      " 

18 

0.000073  " 

0.000076 

4.1       " 

19 

0.000063  " 

0.000060 

4.8       " 

Average  difference  between  two  series    4.6      " 

(voltage  10;  amperage  0.5)  was  only  4.6  per  cent.  Between  the 
weaker  electrical  current  and  the  most  powerful  one  employed  in 
the  work  of  graduation  (voltage  107;  amperage  1.1)  the  average 
difference  in  the  result  of  microscopical  measurements  amounted  to 
7.0  per  cent,  and  for  the  10  different  readings  for  identical  positions 
of  the  secondary  coil,  when  the  second  and  highest  electrical  currents 
were  employed,  the  average  difference  in  result  was  only  4.6  per 
cent.  It  is  likewise  worthy  of  note  that  the  difference  between  the 
readings  for  the  same  position  of  the  secondary  coil,  but  with  dif- 
ferent electrical  potentials,  in  no  case  exceeded  9  per  cent.  It  is, 
therefore,  safe  to  assume  that  the  microscopical  readings  for  the 
excursion  of  the  telephone  plate  as  recorded  in  the  third  column  of 
the  table  on  page  81,  are  reliable  within  10  per  cent,  at  the  outside. 
Indeed,  it  is  also  safe  to  assume  that  the  corrected  figures  represent- 
ing the  actual  excursions  of  the  telephone  plate  for  the  current 
strengths  used  in  the  measurements  of  auditory  acuity  do  not  differ 
from  the  true  values  by  more  than  10  per  cent. 

Knowing  the  excursion  of  the  telephone  plate  caused  by  an  elec- 
trical current  of  107  volts,  1.1  ampere  for  every  position  of  the 
secondary  coil  as  appears  in  column  III.  of  the  table  on  page  81 
and  knowing  also  from  readings  of  three  identical  positions  of  the 
secondary  coil  the  excess  in  excursion  produced  by  the  current  in- 
tensity just  noted,  over  that  normally  obtaining  when  the  hearing 
records  were  made  (voltage  1.9;  amperage  0.5)  it  is  simply  a  matter 
of  arithmetic  to  determine  the  actual  extent  of  excursion  of  the  tele- 
phone plate  corresponding  to  each  of  the  original  hearing  records 
made.  By  dividing  the  values  found  in  column  III.  of  the  table 
(page  81)  by  187,  the  corrected  values  corresponding  to  a  current 
strength  of  1.9  volts;  0.5  ampere,  are  secured  for  every  position  of 
the  secondary  coil  from  1  to  75.  These  are  given  in  Table  XIV. 
below.  Inasmuch  as  an  intensity  of  sound  represented  by  a  posi- 
tion of  the  secondary  coil  nearer  to  the  primary  than  14  centimeters 


THE    GRADUATION    OF    THE   INSTRUMENT 


83 


IS 

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Ill 

aw  •• 


i 


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L 
Ix 


ir 


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X 


X 


X 


k 

X 


X 
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C^C^COCC^lCCOOOTHrHrHCie^ 


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X 


x 


84  THE   HEARING   OF  PRIMITIVE    PEOPLES 

was  not  required  for  any  subject  tested,  values  for  positions  of  the 
secondary  coil  nearer  to  the  primary  than  this  were  omitted  from 
the  tabulations. 

It  will  be  observed  that  while  the  secondary  coil  was  nearer  to 
the  primary  than  27  centimeters  readings  were  made  at  intervals  of 
one  centimeter,  but  for  positions  of  the  secondary  coil  more  distant, 
graduations  were  made  only  at  intervals  of  2  centimeters.  This  plan 
was  followed  since  obviously  the  fall  of  electrical  potential  along  the 
induction  circuit  is  not  directly  as  the  distance.  Indeed,  it  falls  very 
much  more  rapidly  than  this,  and  while  the  change  from  graduations 
at  intervals  of  one  centimeter  to  graduations  at  intervals  of  two  cen- 
timeters does  not  equate  the  steps,  it  does  serve  to  keep  the  records 
from  being  too  widely  dispersed  at  the  upper  end  of  the  curve.  The 
matter  of  inequality  in  steps,  however,  injects  no  inaccuracy  into  the 
final  results,  so  long  as  basically  the  values  of  each  position  are  accu- 
rately determined.  And,  since  each  position  in  these  tests  receives  its 
value  in  ergs  of  sound  energy  emitted  or  centimeter-seconds  of  con- 
densation of  the  sound  wave,  the  question  of  the  number  of  steps  to 
be  made  in  the  tests  acts  as  a  matter  of  convenience  in  manipulation 
only.  It  would  make  but  an  insignificant  difference  in  the  average 
of  any  group  whether  graduations  had  been  made  at  intervals  of 
1  or  2  or  5  centimeters. 

The  excursions  of  the  telephone  plate  (a),  corrected  as  outlined 
above  for  an  electrical  current  of  1.9  volts,  and  0.5  ampere,  appear 
in  the  second  column  of  Table  XIV.,  on  page  83.  In  the  third 
column  are  given  the  values  of  the  condensations  (A)  computed  from 
Wien  's  formula19  already  given,  namely, 


"These  formulae  call  for  certain  measurements  relative  to  the  values  of 
"  k,"  "  c,"  "  N,"  "  R,"  "  a,"  «  p,"  and  "  d,"  respectively.  "  fc,"  which  represents 
the  temperature  coefficient,  is  a  constant  found  from  the  well-known  formula 
of  Keyser  (Phil.  Mag.  38:  256.  1894).  "c"  stands  for  the  velocity  of  sound 
in  air  at  the  temperature  prevailing  when  the  graduations  were  made.  In  the' 
experiments  under  consideration  its  value  was  taken  as  340.2  M.  The  radius 
of  the  free  vibrating  area  of  the  telephone  plate  measured  2.24  cm.  The  sev- 
eral values  of  "  a,"  the  excursion  of  the  telephone  plate  at  its  middle  point, 
appear  in  the  second  column  of  the  table.  The  distance  between  the  ear  and 
the  center  of  the  telephone  plate  "  d  "  throughout  the  entire  series  of  hearing 
tests  was  uniformly  100  cm.  However,  inasmuch  as  the  ear  was  sealed  into 
one  end  of  a  tube  and  the  telephone  into  the  other,  both  to  a  large  extent  air 
tight,  a  value  of  one  centimeter  was  assigned  to  this  distance.  Indeed,  it  is 
improbable  that  the  loss  of  energy  in  a  sealed  tube  would  be  any  considerable 
quantity  for  such  a  short  distance  of  propagation.  The  value  of  "  p,"  the 
temperature  coefficient,  is  0.00128.  "  N  "  equaled  500  D.  V. 


THE    GRADUATION    OF    THE   INSTRUMENT  85 

In  the  fourth  column  are  given  the  values  in  ergs  (centimeter-gram 
seconds)  of  the  quantity  of  sonorous  energy  passing  a  square  centi- 
meter area  perpendicular  to  the  line  of  the  sound  wave 's  progression. 
The  latter  are  computed  from  Lord  Rayleigh's  formula  already 
given,  namely, 


CHAPTER   IX 

METHOD  OF  CONDUCTING  TEST 

ALL  the  measurements  for  simple  auditory  acuity  were  made  in 
the  sound  room,1  and  consequently  under  conditions,  the  most 
favorable  for  quiet  that  it  was  possible  to  secure  at  the  Exposition. 
In  order  to  obtain  a  correct  estimate  of  an  individual's  hearing,  it 
is  very  essential  that  the  test  be  conducted  under  circumstances  as 
favorable  as  possible.  It  is  difficult  to  keep  the  attention  focused 
on  faint  stimuli,  no  matter  through  which  sense  avenue  they  are 
received,  but  faint  auditory  stimuli  are  especially  elusive.  Fatigue 
of  the  auditory  sense  organ  results  after  a  moment  of  stimulation, 
so  that  even  under  the  most  favorable  adjustment  of  external  condi- 
tions, it  is  not  possible  to  continue  an  auditory  test  longer  than 
four  or  five  minutes,  even  with  a  subject  of  far  more  than  average 
intelligence.  Hallucinations  enter  as  very  disturbing  factors.  It 
is  a  common  observation  with  those  who  have  made  tests  of  the 
hearing  of  both  children  and  adults  to  find  that  the  individual 
vigorously  asserts  that  he  hears  the  sound  used  as  a  stimulus  even 
though  the  source  has  been  entirely  removed.  This  is  especially 
true  of  continuous  tones,  or  such  as  follow  in  a  rhythmical  order, 
as  the  ticking  of  a  watch,  or  the  regular  falling  of  water  drops. 

Faint  auditory  sensations  are  likewise  subject  to  decided  illusory 
effects.  Any  extraneous  noises  are  apt  to  be  interpreted  as  the 
tone  to  which  the  subject  is  expectantly  attending.  Such  noises 
as  are  produced  by  the  scraping  of  the  feet  in  walking  over  an 
earthen,  brick  or  cement  floor  are  especially  likely  to  be  heard 
as  the  stimulus  to  which  the  subject  is  directing  his  attention,  if 
a  metallic  click  is  the  stimulus  employed.  Noises  from  the  street 
act  in  the  same  way.  Those  things  which  tend  to  be  distracting 
elements  with  adult  Whites  are  bound  to  be  emphatically  so  in 
tests  on  primitive  peoples  and  younger  children,  whose  power  of 
attention  is  weaker,  and  who  are,  consequently,  more  easily  dis- 
tracted and  are  unable  to  single  out  one  from  among  a  number  of 
somewhat  similar  stimuli  which  they  will  hold  at  the  focus  of  at- 
tention. 

To  overcome  so  far  as  possible  the  error  which  might  creep  in, 
on  account  of  the  elements  just  enumerated,  a  check  method  sug- 

1  For  a  description  of  this  booth  the  reader  is  referred  to  the  foot-note  on 
page  30. 

86 


METHOD   OF   CONDUCTING    TEST  87 

gested  by  Professor  Cattell  was  introduced.  This  consisted  in  hav- 
ing the  subject  interpret  and  give  back  what  he  received.  The  test 
in  consequence  is  a  little  more  than  a  measure  of  pure  sensation— if 
a  measure  of  pure  sensation  is  ever  possible.  Instead  of  presenting 
the  ''makes  and  breaks"  in  rapid  succession  without  reference  to 
number  or  manner,  as  is  ordinarily  done  with  the  telegraph  key, 
or  the  "make  and  break"  mechanism  of  the  Seashore  audiometer, 
I  gave  the  stimuli  in  groups  or  rhythms;  that  is,  a  series  might 
be  presented  in  which  two  clicks  in  rapid  succession  would  be  fol- 
lowed by  a  pause  of  two  seconds,  the  two  clicks  repeated  and  so 
on.  Or,  the  series  might  be  given  in  singles  or  in  groups  of  three 
clicks  followed  by  a  rest  of  a  couple  of  seconds.  Graphically,  the 
series  might  be  represented  as  follows :  --,,,--,,,--,,,--,,,  etc., 
in  which  the  dashes  represent  the  order  of  the  stimuli  and  the 
commas,  pauses  or  silence.  A  group  of  three  clicks  would  be  repre- 
sented by  the  following  scheme:  ---,,,,---,,,,---,,,,---,,,, 
etc.,  and  a  rhythm  of  single  clicks  by  the  following :  -,,,,-,,,,- 
5  >  >  i  - 1  j  >  j  -  5  >  9  9  etc.  I  pursued  no  set  order  of  presenting  the  series, 
so  that  it  might  not  be  possible  for  the  subject  to  anticipate  the 
answer  which  he  would  be  expected  to  give. 

The  number  of  clicks  to  a  group,  I  found,  had  to  be  limited  to 
three.  I  discovered  that  many  of  the  primitive  peoples  were  unable 
to  count  the  stimuli  following  each  other  as  rapidly  as  did  these 
with  any  degree  of  facility  in  groups  larger  than  two  or  three. 
Children,  too,  I  afterward  learned,  can  catch  a  rhythm  of  three 
but  experience  difficulty  with  one  of  four  or  five. 

Such  a  method  of  presenting  the  stimuli,  as  has  just  been  indi- 
cated, in  a  manner  supplies  the  deficiencies  arising  from  the  neces- 
sity of  employing  non-significant  stimuli  in  testing  hearing. 
Indeed,  to  a  considerable  degree,  the  test  is  one  of  which  the  elements 
are  significant ;  that  character  being  attached  to  them  by  the  count- 
ing operation.  The  test,  moreover,  has  other  advantages.  It  does 
away  with  the  necessity  of  depending  upon  the  cooperation  of  the 
subject— a  necessity  present  in  almost  all  other  methods  for  measur- 
ing hearing.  It  presents  something  tangible,  as  it  were,  for  the 
attention  to  attach  itself  to.  The  subject,  when  the  ordinary 
methods  are  followed,  finds  that  as  the  sensation  becomes  increas- 
ingly more  faint,  it  is  impossible  for  him  to  organize  his  mental 
processes  to  the  extent  of  arriving  at  a  certain  conviction  as  to 
whether  he  actually  hears  the  tone  or  not.  Where  the  method  of 
reproduction  is  followed,  this  element  of  uncertainty  does  not,  in 
any  way,  enter  into  the  results. 

In  all  cases,  I  chose  as  the  threshold  that  point  where  the  subject 


88  THE   HEARING   OF  PRIMITIVE    PEOPLES 

failed  to  indicate  accurately  the  character  of  the  stimuli  presented. 
In  the  neighborhood  of  the  threshold  values,  I  made  it  a  point  to 
vary  the  character  of  the  stimulation  frequently  without  changing 
its  intensity.  This  was  done  to  make  certain  that  the  subject's 
responses  were  not  pure  guesses.  It  was  found,  however,  that  in 
case  of  almost  all  persons,  there  is  a  subconscious  evaluation  given  to 
such  estimates  which  are  wholly  valid.  When  the  subject  stated 
that  he  was  uncertain  as  to  the  character  of  the  sensation,  whether 
the  ticks  came  in  twos,  threes  or  ones,  he  was  told  to  express  a 
judgment  and  it  so  happened  that  frequently  the  subject  judged 
correctly  every  variation  made  with  a  given  intensity  although  he 
asserted  that  his  estimations  were  in  every  case  pure  guesses. 


CHAPTER   X 

RESULTS 

THE  nature  of  the  data  as  regards  auditory  acuity  is  such  as  to 
make  them  somewhat  difficult  to  present  intelligibly.  These  data 
relating  specifically  to  auditory  acuity  are  given  both  in  terms  of  the 
condensation  of  the  sound  wave  leaving  the  telephone  and  the  actual 
energy  in  ergs  (centimeter-gram-seconds)  exerted  by  the  sound  wave 
over  a  square  centimeter  of  surface  at  the  same  point.  Since  the 
energy  required  to  produce  a  tone  of  threshold  value,  in  an  ear  of 
ordinary  sensitivity,  amounts  to  less  than  a  ten-millionth  part  of  an 
erg,  it  is  at  once  clear  that  the  data  we  are  working  with  are  compre- 
hensible, popularly,  only  in  mathematical  terms.  TJie  data  to  be 
presented,  however,  are  to  be  employed  for  comparative  purposes 
only,  so  that  the  absolute  values  are,  relatively,  of  insignificant  mo- 
ment. To  know  that  one  group  of  people  possesses  a  hearing  sensi- 
tivity two,  or  ten,  or  one  hundred  times  as  great  as  another,  does  not 
call  for  an  understanding  of  the  absolute  unit  used,  if  only  the  unit 
remains  constant  from  one  series  of  measurements  to  another,  and 
besides,  possesses  the  additive  character.  The  figures  representing 
the  condensation  as  well  as  the  actual  quantity  of  sound  energy  being 
dispersed  fulfill  both  requirements,  and  hence  no  inaccuracy  will 
result  if  the  reader  ignores  the  fractional  factor  altogether,  and 
thinks  of  the  results  in  terms  of  the  first  p«art  of  the  figure  only,  e.  g., 
in  terms  of  "1.4"  instead  of  "1.4X  lO"9."  And  in  the  eyes  of 
many  readers  such  a  method  of  interpreting  the  complex  data  which 
follow,  will  contribute  both  to  their  clearness  and  ease  of  compre- 
hension.1 

In  Table  XV.  are  presented  these  figures  in  detail,  indicating  the 
race;  number  of  cases  included  in  the  average;  the  average  result, 
stated  in  terms  of  atmospheres  of  pressure,  and  ergs  (centimeter- 
gram-seconds)  ;  the  average  deviation  from  this  average ;  and  the 
standard  deviation.  From  the  latter,  it  is  possible  to  compute  di- 
rectly any  other  measures  of  the  variability  that  may  be  desired. 
The  data  are  given  for  both  the  right  and  the  left  ear.  A  word, 
perhaps,  is  necessary  concerning  the  make-up  of  the  respective 
groups.  For  a  test  of  this  kind,  as  was  noted  in  connection  with  the 

1  For  details  relating  to  the  physical  graduation  of  the  instrument  em- 
ployed in  the  acuity  test,  the  reader  is  referred  to  Chapter  VIII. 

89 


90 


TEE   HEARING   OF  PRIMITIVE   PEOPLES 


data  on  the  upper  threshold  of  hearing,  already  presented,  it  was 
thought  best  to  reject  those  individual  hearing  records  where  there 
was  definite  reason  to  believe  that  the  case  was  one  of  pathological 
hearing.  In  pursuance  of  this,  therefore,  I  rejected  in  this  series  of 
measurements  the  data  from  every  person  who  consciously  had  ex- 
perienced difficulty  in  hearing.  Obviously,  so  long  as  the  rejections 
follow  some  consistent  plan,  no  inaccuracy  need  result  and  I  do  not 

TABLE    XV 
AUDITORY  ACUITY 

In  Terms  of  the  Condensation  of  the  Sound  Wave  Leaving  the  Instrument 
and  also  in  Terms  of  the  Energy  in  Ergs  Leaving  the  Same 


Right 

Ear 

L< 

;ft  Ear 

No.  of 
Cases 

Average 
A  =  1(T9 

A.  D. 

S.  D. 

Average 
E=lQ-'r  ergs 

Average 
A  =  10~9 

A.  D. 

S.D. 

Average 
J?  =  10-7ergs 

Whites 

151 

56 

385 

502 

7.9 

7.2 

506 

509 

13  2 

Indians 
(School)... 
Filipinos  
Coco  pa  In- 
dians    

64 
137 

10 

7.5 
24.2 

7.3 

3.63 
14.57 

286 

5.18 
18.30 

3.49 

14.2 
147.8 

16.01 

8.5 
26.6 

9.0 

4.09 
14.46 

5.30 

5.79 
17.81 

6.34 

18.2 
178.6 

30.2 

Vancouver 
Indians  
Patagonian 
Indians  
Ainu          . 

7 

3 

8 

10.01 

12.3 
18.1 

5.01 

8.43 
1164 

5.69 

8.97 
1638 

38.1 

38.1 

82.7 

10.03 

17.0 
17.1 

5.95 

8.59 
8.71 

6.66 

9.57 
1136 

36.5 

73.0 
73  4 

Pigmies  

5 

10.3 

3.55 

4.44 

26.8 

7.5 

1.24 

1.32 

14.2 

A  =  condensation  of  sound  wave  at  the  instrument. 

E  =  energy  in  ergs  of  sound  wave  leaving  the  instrument. 

A.  D.  =  average  deviation. 

S.  D.  =  standard  or  the  mean  square  deviation. 


TABLE    XVI 
AUDITORY  ACUITY 

In  obtaining  the  averages  given  in  this  table,  the  lowest  25  per  cent,  and 
the  highest  25  per  cent,  of  each  group  were  omitted,  leaving  only  the  middle 
half. 


Right  Ear 

Left  Ear 

- 

No.  of 
Cases 

Average 
A=10-» 

A.D. 

Average 

E=vy-1 

ergs 

Average 
A=10-9 

A.  D. 

Average 
E=10-7 
ergs 

Whites.  
Indians  
Filipinos  

78 
33 
81 

3.9 
6.1 
16.5 

6.922 

1.40 
5.29 

3.84 
9.61 
68.73 

4.9 
5.0 

18.8 

1.33 
1.03 
6.02 

6.06 
6.31 
89.21 

A  =  the  condensation  of  the  sound  wave  at  the  instrument. 
E  =  the  energy  of  the  sound  wave  in  ergs   per  square  centimeter  area 
leaving  the  instrument. 


RESULTS 


91 


think  that  the  rejection  of  the  records  of  some  twenty  individuals, 
for  the  reason  indicated,  influenced  the  character  of  the  results 
otherwise  than  to  raise  the  average  for  each  group  to  an  appre- 
ciable extent.  For  such  large  groups  as  those  of  the  Whites,  In- 
dians, or  the  Filipinos,  a  sifting  of  the  records,  perhaps,  would  have 
been  unnecessary,  but  in  case  of  some  of  the  smaller  groups,  with 
fewer  than  ten  individuals,  any  one  specially  poor  record  would 

TABLE   XVII 

RIGHT  EAB 
Showing  the  Distribution  of  the  Individuals  with  Respect  to  Auditory  Acuity 


Intensity  of 
Sound, 
A  =  X  10-9 

Whites 

Indians 
(from 
School) 

Filipinos 

Cocopa 
Indians 

Van- 
couver 
Indians 

Pata- 
gonian 
Indians 

Ainu 

Pigmy 

1.4 

1 

1.5 

3 

1.6 

4 

1.8 

7 

1.9 

6 

1 

2.1 

5 

1 

2.3 

9 

2 

2.5 

6 

1 

3 

2.8 

9 

3 

1 

3.0 

13 

2 

2 

3.3 

9 

2 

3 

1 

1 

3.6 

9 

2 

3 

4.0 

7 

4 

2 

2 

1 

4.5 

6 

4 

2 

1 

5.0 

6 

5 

2 

1 

5.5 

7 

4 

2 

1 

6.2 

6 

3 

4 

4 

1 

2 

7.1 

5 

4 

5 

1 

8.1 

2 

7 

6 

1 

9.1 

4 

5 

8 

1 

10.4 

6 

4 

7 

1 

11.9 

5 

4 

7 

1 

1 

1 

14.1 

3 

2 

9 

1 

15.7 

0 

1 

10 

18.1 

2 

0 

9 

1 

1 

21.1 

1 

1 

8 

1 

25.0 

2 

1 

8 

1 

1 

29.9 

1 

7 

1 

36.5 

6 

2 

43.4 

5 

52.5 

5 

64.8 

6 

82.3 

3 

99.9 

2 

affect  the  standing  of  the  group  to  such  an  extent  as  to  make  the 
figure  for  the  average  wholly  unrepresentative  and  false.  Yet,  in 
spite  of  corrections  and  eliminations,  it  is  quite  evident  that  all 
pathological  cases  were  not  excluded,  as  appears  from  a  comparison 
of  the  data  presented  in  tables  XV.  and  XVI.  In  Table  XVI.,  I 


92 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


TABLE    XVIII 

LEFT  EAR 
Showing  the  Distribution  of  the  Individuals  with  Respect  to  Auditory  Acuity 


Intensity  of 
Sound, 
A  =  XlO-» 

Whites 

Indians 
(from 
School) 

Filipinos 

Cocopa 
Indians 

Van- 
couver 
Indians 

Pata- 
gonian 
Indians 

Ainu 

Pigmy 

1.4 

1 

1.5 

2 

1.6 

3 

1.8 

3 

1.9 

4 

1 

2.1 

4 

1 

2.3 

5 

1 

2.5 

7 

3 

1 

2.8 

7 

2 

3.0 

8 

3 

3.3 

11 

4 

4 

1 

3.6 

12 

4 

4.0 

8 

5 

2 

1 

4.5 

8 

6 

2 

5.0 

7 

5 

4 

2 

1 

5.5 

6 

4 

3 

6.2 

8 

2 

4 

2 

1 

2 

7.1 

5 

3 

4 

1 

1 

8.1 

5 

3 

5 

1 

1 

9.1 

5 

3 

7 

2 

10.4 

4 

2 

6 

11.9 

5 

2 

6 

3 

14.1 

4 

2 

8 

1 

1 

15.7 

3 

1 

12 

1 

18.1 

4 

1 

11 

1 

1 

1 

21.1 

4 

1 

9 

1 

25.0 

2 

2 

9 

1 

29.9 

3 

1 

7 

1 

1 

36.5 

7 

43.4 

1 

6 

1 

52.5 

1 

8 

64.8 

4 

1 

82.3 

3 

99.9 

3 

127.2 

2 

1 

162.5 

1 

214.9 

1 

rejected  the  25  per  cent,  of  the  records  at  the  top  and  the  same 
number  at  the  bottom,  leaving  one  half  of  all  the  records  distributed 
normally  about  the  median.  Were  the  distribution  of  cases  normal, 
such  a  method  of  procedure  would  affect  the  average  result  only  to  a 
very  slight  degree.  It  will  be  noted  on  the  contrary,  however,  that 
the  average  has  been  shifted  upward  decidedly  in  the  case  of  every 
group.  In  fact,  this  sifting  has  the  effect  of  almost  doubling  each 
average,  thus  reducing  the  quantity  of  energy  necessary  to  excite  an 
auditory  sensation,  on  the  average,  by  one  fourth. 

In  tables  XVII.  and  XVIII.  are  shown  the  general  distributions 
of  the  individual  records,  as  they  appear  in  the  several  groups. 


RESULTS  93 

These  distributions  have  been  made  in  parallel  columns  to  facilitate 
the  study  of  comparisons.  The  tables,  likewise,  show  the  character 
of  the  curves  that  the  hearing  records  of  the  several  groups  offer, 
and  in  addition,  present  them  in  such  form  that  group  differences 
are  directly  apparent  and  recognizable.  Such  a  form  of  distribu- 
tion makes  unnecessary  the  use  of  graphic  curves. 

In  Table  IV.,  p.  34,  are  given  the  distributions  of  the  individuals 
of  the  three  most  numerous  groups  according  to  age.  All  the  data 
relating  to  the  smaller  groups  will  be  presented  in  detail  in  con- 
nection with  the  discussion  of  their  several  individual  results. 
Again,  making  a  cursory  review  of  the  data  in  Table  IV.  the  fact 
is  revealed  that  in  case  of  the  Whites,  Indians,  and  Filipinos,  the 
age  lines  were  rather  closely  drawn.  I  accepted  the  record  of  no 
individual  whose  age  exceeded  30  years  or  fell  below  16.  This 
was  done  as  in  the  case  of  the  data  relating  to  the  upper  threshold 
of  hearing,  in  order  to  secure,  so  far  as  practicable,  homogeneous 
groups.  The  average  age  of  the  Whites  selected  was  found  to  be  23 
years  and  5  months;  of  Indians,  19  years  and  2  months;  and  of 
the  Filipinos,  21  years  and  1  month.  For  an  acuity  test  I  do  not 
think  this  difference  in  average  age  is  such  as  to  be  very  significant. 

We  shall  now  proceed  to  a  consideration  of  the  data  in  detail : 

Whites.— Whites,  such  as  those  selected  for  these  tests,  indi- 
viduals in  the  prime  of  life,  men  and  women  who  have  never  ex- 
perienced any  difficulty  in  hearing,  according  to  these  experimental 
data  are  able  to  sense  and  interpret  on  the  average,  a  stimulus  pro- 
duced by  the  action  of  an  air  wave,  amounting  to  a  pressure  differ- 
ence of  5.5  X  10~9  atmospheres  or  7.5  X  10~7  ergs.  This  indeed  is  a 
pressure  difference  smaller  than  it  is  possible  to  secure  in  the  most 
rarified  vacua* 

It  is  rather  difficult  to  compare  this  value  with  the  figures  which 
have  been  obtained  by  other  observers,  largely  because  of  the  dif- 
ferent experimental  conditions  under  which  the  tests  have  been 
made.  In  the  first  place,  I  have  been  unable  to  find  data  based  on 
the  measures  of  more  than  a  dozen  individuals,  and,  indeed,  since 
the  range  of  individual  differences  in  hearing  acuity  is  as  100  to  1, 
within  a  single  group,  any  discrepancies  which  exist  may  very 
plausibly  be  accounted  for  because  of  the  paucity  of  numbers  con- 
stituting the  groups  compared.  Again,  Wien3  has  shown  that  the 
ear's  sensitivity  for  tones  is  a  function  of  their  pitch,  and  that  its 
sensitivity  for  different  pitched  tones  varies  within  rather  extreme 
limits.  The  vibration  number  of  the  tone  used  is,  consequently,  no 

2  See  Rayleigh,  Phil.  Mag.  38 :  300.    1894. 
*Pfliiger's  Arch.  97:   1.    1903. 


94  THE   HEARING   OF  PRIMITIVE   PEOPLES 

doubt,  also  an  important  factor  in  accounting  for  discrepancies 
noted. 

The  vibration  frequency  of  the  tone  I  employed  I  could  not 
definitely  establish.  After  repeated  assays  to  fix  the  dominant  tone 
by  comparison  with  other  tones  of  known  vibration  frequencies,  I 
finally  selected  500  double  vibrations  as  being  most  nearly  correct. 
But,  although  I  think  the  dominant  tone  did  not  vary  far  from 
500,  there  is  no  question  but  that  some  very  pronounced  over-tones 
present  were  quite  effective  in  favoring  acuity.  Wien's4  figures  for 
a  tone  of  approximately  400  D.  V.  was  1.2  X  10'10  (E  =  8.0  X  10'11 
ergs)  for  his  own  ear,  when  a  telephone  instrument  furnished  the 
sound.  The  figure  was  practically  the  same  with  a  tuning  fork  and 
the  Helmholtz's  resonators,  namely,  8.0  X  10'10  (#  =  3.6X10-' 
ergs).5  Wien's  results,  however,  make  the  ear  to  be  almost  one 
hundred  times  more  sensitive  than  the  experimental  results  of 
previous  observers  had  led  them  to  believe.  For  example:  Toepler 
and  Boltzmann,6  who,  according  to  Lord  Rayleigh,  were  the  first 
to  make  an  experimental  determination  of  this  question  found,  with 
tuning  forks,  that  the  value  of  a  sound  wave's  condensation  at  the 
ear,  to  be  just  audible,  was  6.5  X  10~8.  This  figure  differs  but 
slightly  from  Lord  Rayleigh 's  own  conclusions  from  experiments 
.with  Wolf's  bottle7  where  A  =  4.1  X  10'8  for  a  tone  of  2,730  D.  V. 
The  same  writer  found  A  =  4.6  X  10~8  when  a  tuning  fork8  of  512 
D.  V.  was  employed  as  the  source  of  sound. 

Professor  Wead,9  also  employing  tuning  forks  found  for  a  tone 
of  c2  that  A  =  7.1  X  lO'9  (E  =  1.1  X  10'6  ergs)  was  still  audible. 
P.  Ostmann10  with  tuning  forks  (256  D.  V.)  places  the  threshold 
at  A  =  2.1  X  10-8  (#  =  8.0  X  10-6  ergs).  These  latter  results  are 
pretty  much  in  accord  with  some  recent  experiments  of  Zwaarde- 
maker  and  Quix,11  who  find  that  tones  from  a  tuning  fork  of  pitch 
c2  in  which  A  =  1.5  X  10~8  (E  =  5.4  X  10'6  ergs)  might  still  be 
heard.  More  recently  still,12  they  secured  a  somewhat  smaller 
figure  A  =  7.1X10-9  (#  =  1.3X10-*  ergs).  Lord  Rayleigh 's 
results  from  his  telephone  experiments  lead  him  to  think  his  previous 
figures  placed  the  sensitivity  of  the  ear  too  low,  since  some  of  his 

'Pftiiger's  Arch.  97:  33.    1903. 

6  Dissert,  s.  46,  1888;  also,  Wied.  Annal.  36:  849.    1889. 

6  See  Lord  Rayleigh,  "  Theory  of  Sound,"  II.,  p.  433. 

7Proc.  Roy.  Soc.  26:  248.    1877. 

9  Phil.  Mag.  38:  270.    1894. 

•  Amer.  J.  of  Sci.  36:  36.    1883. 

10 Arch.  f.  (Anat.  u.)  Physiol.  1903,  S.  321. 

"Arch.  f.   (Anat.  u.)  Physiol.  1902,  S.  393. 

"Ztschr.  f.  Psych.  33:  401.    1904. 


RESULTS  95 

subjects  were  able  to  still  hear  when  A  =  1.1  X  10'9  (E  =  2.8  X  10'8 
ergs).  The  first  figure  is  about  the  same  (A  =  8.88  X  10~9)  as  has 
more  recently  been  gotten  by  Webster13  with  his  "phone." 

It  was  noted  above  that  Wien's  figures  are  from  40  to  100  times 
smaller  than  my  own  and  those  of  the  other  investigators.  Zwaar- 
demaker  and  Quix14  attribute  Wien's  excessive  sensitivity  of  the 
ear  to  the  fact  that  the  telephone  receiver  was  held  snugly  against 
the  ear  and  that  hearing  was  assisted  by  molecular  bone  conduction 
in  addition  to  the  molar  sound  energy  passing  over  the  ossicles. 

From  the  character  of  my  own  data  it  is  easy  to  explain  differ- 
ences in  auditory  acuity  as  great  as  20  times,  such  as  have  been 
obtained  by  different  observers,  where  experiments  have  been  limited 
to  a  few  subjects.     Among  my  white  subjects,  although  not  a  single 
individual  had  ever  observed  any  diminution  in  his  hearing  func- 
tion, the  person  with  the  best  acuity  required  about  400  times  less 
energy  to  just  excite  an  auditory  sensation  than  did  the  one  who 
heard  most  poorly.     And,  indeed,  the  individual  with  the  keenest 
ears  heard  about  90,000  times  as  well  as  did  the  poorest  among 
Filipinos,  although  in  conversing  with  these  Filipinos  it  was  not 
possible  to  detect  any  hearing  deficiency.     Wien15  reported  two  cases 
of  individuals  who  are  still  able  to  hear  loud  speech  but  whose  hear- 
ing is  from  one  to  ten  million  times  poorer  than  normal.     Ostmann16 
concluded  that  a  dimunition  of  hearing  of  one  half  or  one-third  is  of 
slight    consequence.     The    range    of   efficiency    in    hearing    among 
normally  hearing  people  is  a  question  which,  to  my  knowledge,  has 
never  before  been  investigated  in  this  way.     Ordinarily,  it  appears 
unreasonable  to  believe  that  in  speech  the  human  voice  covers  such 
wide  latitudes  of  intensity  that  a  person  can  speak  300  or  indeed 
1,000,000  times  as  loud  at  one  time  as  at  another  and  yet  not  be 
speaking  appreciably  loud.     Our   difficulty,   perhaps,   arises  from 
comparing  a  hearing  test  such  as  the  one  under  consideration,  with 
the  ordinary  visual  acuity  tests  in  which  the  units  are  the  angles 
subtended  by  light  rays  coming  from  opposite  parts  of  the  letters. 
These  tests  obviously  are  incomparable.     But  only  recently  von 
Kries17  has  shown  that  the  minimum  intensity  of  light  necessary 
to  excite  the  eye  amounts  to  only  1.3  to  2.6  X  10'10  ergs.     To  see  an 
object,  5.6  X  10~10  ergs  is  essential,  about  the  same  quantity  of  energy 
that   Wien   discovered   necessary   for   sound,    and   about   %o   the 

13  Boltzmann-Festschrift,  1904,  p.  874. 
"Ztschr.  f.  Psych.  33:  408.    1904. 
"Pfluger'sArch.97:37.    1903. 
"Arch,  of  Otology,  34:  207.    1905. 
"Ztschr.  f.  Psychol.  u.  s.  w.  41:  393.    1907. 


96  THE   HEARING   OF   PRIMITIVE   PEOPLES 

quantity  necessary  to  excite  a  sensation  of  sound  on  the  average 
according  to  my  own  experimental  results.  Between  the  intensity 
2.6  X  10~10  ergs  and  that  of  ordinary  moonlight,  the  difference  is 
millions,  and  between  the  intensity  of  moonlight  and  that  of  sun- 
light, there  is  again  a  difference  of  at  least  100,000.  It  is  such 
differences  with  respect  to  the  eye  which  have  their  counterpart  in 
the  field  of  hearing.  Indeed,  extremely  great  differences  in  the  in- 
tensity of  tones  are  not  so  commonly  noticed  as  one  would  think. 
The  singing  of  a  thousand  voices,  though  noticeably  louder  than  that 
of  a  single  singer,  certainly  does  not  appear  1,000  times  as  great. 
Under  certain  atmospheric  conditions  in  the  quiet  country,  it  is 
possible  to  hear,  quite  distinctly,  a  human  voice  at  a  distance  of  two 
miles.  If  the  loudness  of  the  voice  when  at  a  distance  of  11,000  feet 
be  compared  with  that  when  audible  only  10  feet  from  the  speaker, 
some  conception  may  be  had  of  differences  of  intensity  amounting 
to  at  least  10,000  to  1  and  perhaps  1,000,000  to  1.  In  the  light 
of  such  comparisons  the  figures  showing  the  range  of  sensitivity  of 
the  normal  ear  are  not  exceptionally  striking. 

It  will  be  noted  that  not  only  in  the  case  of  Whites  but  in  those 
of  the  records  of  all  of  the  groups,  the  average  deviations  are  ex- 
tremely large.  Such  of  necessity  must  be  the  case,  however,  when 
the  unit  of  measurement  is  extremely  small,  such  as  are  physical 
units  of  sound.  Although  such  fineness  of  measurement  is  not 
essential,  it  can  not  well  be  avoided.  Our  units  are  fixed  beforehand 
and  with  these  we  are  measuring  physiological  and  psychological 
conditions  as  they  are  found  among  individuals.  Part  of  the  large 
average  deviation,  indeed,  may  also  be  explained  by  the  dispropor- 
tionately large  number  of  the  cases  found  below  the  mode  in  the 
curve,  which  arises  from  the  inability  which  we  experience  to  mark 
off  accurately  the  normal  from  the  pathological  in  any  functioning. 
In  a  way,  I  sought  to  eliminate  some  of  the  error  arising  from  this 
source  by  presenting  an  average  of  the  mean  cases  only,  as  appears 
in  Table  XVI.  But,  even  under  such  restrictions,  the  average  devia- 
tion amounts  to  about  one  third  of  the  average  result  in  each  of  the 
several  groups.  From  this  it  appears  that  so  far  as  the  hearing 
function  goes,  individuals  do  not  distribute  themselves  so  as  to  con- 
form closely  to  the  laws  governing  the  normal  frequency  curve. 

Indians. —  (For  a  more  detailed  description  of  this  group,  see 
Chapter  II.)  The  64  Indians  tested  for  simple  auditory  acuity, 
whose  records  are  here  presented,  are  the  same  whose  records  formed 
the  basis  of  the  study  on  the  upper  threshold  of  hearing  for  Indians, 
as  already  presented.  Included  in  this  group  are  the  records  of  14 
full-blooded  males  and  13  mixed  bloods,  with  4  full-blooded  females 


RESULTS  97 

and  33  mixed  bloods.  Five  of  those  tested  were  over  25  years; 
81  per  cent,  were  between  the  ages  of  16  and  20  years.  (See 
Table  IV.,  p.  34.) 

It  must  be  recalled  that  these  Indians  included  under  the  general 
caption  "Indian"  were  those  only  attending  the  Model  Indian 
School  at  the  Exposition,  who,  previous  to  their  coming  to  St.  Louis 
had  been  in  attendance,  for  some  considerable  time,  at  various 
Indian  schools  throughout  the  United  States.  As  has  already  been 
pointed  out,  in  habits  and  culture  they  are  to  be  distinguished  from 
the  Indian  of  the  forest  and  plain,  hence,  my  reason  for  grouping 
together  all  these  Indians  from  the  schools  representing  a  number 
of  different  tribes.  For  the  same  reason  I  have  chosen  to  consider 
separately  those  tribes  representing  Indians  who  came  from  their 
natural  habitats,  and  who,  therefore,  more  nearly  constitute  what 
might  be  called  representatives  of  the  typical  Indian. 

For  the  right  ear,  the  figure  representing  the  condensation  of  a 
sound  wave  which  on  the  average  is  required  to  just  excite  the  organ 
of  hearing  of  the  Indians  at  the  Model  Indian  School,  is  7.5  X  10~9 
(E  =  14.2  X  10-7  ergs)  and  for  the  left  ear  8.5  X  10'9  (E  =  18.2  X 
10~7  ergs).  The  figure  for  the  right  ear  is  1.34  times  larger  than 
that  for  the  corresponding  ear  of  Whites,  and  for  the  left  ear  1.18 
times  larger.  On  account  of  the  relatively  large  average  deviations 
these  differences  are  not  so  significant  as  at  first  hand  one  might 
suppose.  Still,  the  mathematical  probability  of  a  difference  in 
favor  of  Whites  is  not  unimportant.  On  the  basis  of  the  data,  the 
chances  are  nearly  200  to  1  in  favor  of  the  superior  auditory  sense 
of  Whites  for  the  right  ear,  and  6  to  1  in  case  of  the  left  ear. 
Arguing  from  Table  XVI.,  where  the  individual  records  included  in 
the  average  are  restricted  to  those  lying  about  the  mean,  the  superi- 
ority of  the  hearing  of  Whites  over  Indians  is  more  strikingly  brought 
out,  especially  as  regards  the  right  ear.  The  average  for  Whites 
shows  a  keenness  of  hearing  which  is  just  about  two  times  that  for 
Indians.  In  the  averages  of  the  left  ear,  however,  the  size  of  the 
difference  between  the  two  groups  is  lessened,  a  condition,  no  doubt, 
due  to  the  fewness  of  the  individuals  comprising  both  the  groups 
under  comparison. 

Where  the  individual  records  are  so  widely  dispersed  as  are  these, 
instead  of  grouping  themselves  rather  closely  about  the  mode,  the 
character  of  the  distribution,  as  a  whole,  is  really  more  significant 
in  the  way  of  indicating  group  differences  than  the  figures  repre- 
senting the  averages  of  the  two  groups  to  be  compared.  A  compari- 
son of  the  hearing  of  Indians  and  Whites  respectively  can  easily  be 
made  by  reference  to  tables  XVII.  and  XVIII.,  where  the  individual 


98 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


records  have  been  distributed  according  to  relative  position.  It  is 
clearly  apparent  that  the  modes  of  the  distributions  of  the  Indian 
hearing  records— if  such  a  term  as  "mode"  is  really  applicable  to 
such  a  form  of  distribution— fall  rather  decidedly  lower  than  do 
those  in  the  curves  of  Whites.  Moreover,  it  is  seen  that  the  general 
distributions  of  the  hearing  records  for  Whites  stand  distinctly 
higher  than  do  those  for  Indians  for  both  ears,  demonstrating  that 
Whites  as  a  whole  hear  better  than  do  Indians,  although  many  of 
the  Indians,  to  be  sure,  possess  ears  that  are  more  acute  than  the 
average  acuity  for  Whites.  Of  the  64  Indians,  however,  the  ears  of 
13  only,  or  about  20  per  cent.,  rank  as  high  as  the  median  record  for 
American  or  European  ears  as  regards  the  right  ear,  and  for  the  left, 
24  Indians  hear  better  than  the  median  hearing  record  for  Cau- 
casians, or  about  38  per  cent.  Taken  all  in  all,  therefore,  the  data 
point  rather  decidedly  toward  a  superiority  of  the  hearing  of  Whites 
over  that  of  Indians;  such  Indians  at  any  rate  as  constitute  the 
groups  here  considered. 

The  numbers  are  rather  small  to  indicate  reliable  sex  differences ; 
27  men  and  37  women.  But  the  average  acuity  of  the  men,  for  the 
right  ear,  amounted  to  A  =  7.4  X  10~9  (#  =  1.38  X  10~6  ergs) ;  of 
the  women  for  the  same  ear  it  was  A  =  7.5  X  10'9  (E  =  1.42  X  10~6 
ergs).  For  the  left  ear,  the  figures  for  men  and  women  respectively 
were  A  =  8.5  X  10'9  (E  =  1.83  X  lO'6  ergs)  and  A  =  8.4  X  10'9 
(E  =  1.78  X  10~6  ergs).  If  we  should  argue  from  this  group  alone, 
therefore,  sex  differences  in  hearing,  among  Indians,  do  not  exist. 

The  Cocopa  (or  Seri)  Indians.— (For  a  more  detailed  description 
of  these  people,  turn  to  Chapter  II.,  page  6.)  Of  the  Cocopa 
Indians  I  was  able  to  secure  ten  hearing  records,  all  of  males.  Owing 
to  the  fact  that  the  number  is  so  small,  I  shall  present  the  data 
relating  to  the  hearing  of  the  various  individuals  in  detail : 


ATIDITOBY  ACUITY 


Name 

A  pp 

Rig] 

it  Ear 

Le 

ft  Ear 

Age 

(A  =  XlO-») 

(£=XlO-7ergs) 

(A-xi<r») 

(£='X  10-'  ergs) 

Skik  

14 

6.2 

9.5 

8.1 

17.0 

El  Puck.. 
Hi  

15 

8 

6.2 
4.0 

9.5 
4.0 

6.2 
5.0 

9.5 
6.3 

Jack  

17 

6.2 

9.5 

5.0 

6.3 

Mert.  
John  Boy 
Joe  

14 
18 
?,0 

11.9 
6.2 
14.1 

35.0 
9.5 
49.0 

(64.8) 
2.5 
18.1 

(1050.0) 
1.6 
80.0 

Jerry  
Pablo  
Tom  .   .. 

42 
55 

70 

3.3 

(64.8) 
(214  9) 

2  8 
(1080.0) 

(8260.0) 

6.2 
21.1 
(214.9) 

9.5 
110.0 
(8260.0) 

Average. 

7.28  X10-9 

16.1X10-7 

9.02X10-9 

30.2X10-7 

RESULT8  99 

It  will  be  observed  that  the  individual  differences  are  consider- 
able, which  makes  the  average  of  relatively  little  value  as  a  figure  to 
represent  the  hearing  efficiency  of  the  group.  Of  the  ten  hearing 
records  made,  I  rejected,  as  being  palpably  pathological,  two  for  the 
right  ear  and  two  for  the  left;  those  which  have  been  enclosed  in 
parentheses.  Even  with  the  elimination  of  these  records,  not  only 
on  the  average  but  in  almost  every  individual  case  the  records  for 
the  Cocopas  are  below  the  median  record  of  Whites  for  both  the 
right  and  the  left  ears.  The  single  exceptions  to  this  statement  are 
that  of  Jerry,  whose  record  for  the  right  ear  is  slightly  superior  to 
the  median  record  for  the  Whites,  and  that  of  John  Roy,  who  hears 
slightly  better  with  his  left  ear  than  the  median  of  Whites.  Some 
of  the  auditory  deficiency  manifested  by  these  people  is  undoubtedly 
mental,  but  it  is  improbable  that  all  can  be  attributed  to  this  factor, 
inasmuch  as  some  of  the  individuals  tested  were  fairly  bright  young 
men  and,  moreover,  took  a  decided  interest  in  the  hearing  test. 
I  questioned  some  of  the  men  as  to  their  apparent  hearing  deficiency, 
with  the  result  that  the  difficulty  was  attributed  to  ear  afflictions, 
from  which  it  appeared  almost  every  individual  had  suffered  in  time 
past.  These  were  said  to  be  due  to  exposure  to  storms  and  inclement 
weather.  But  why  the  Cocopa  Indian  should  particularly  be  a  vic- 
tim to  the  inclemency  of  the  weather,  it  is  hard  to  imagine,  inasmuch 
as  he  dwells  in  a  tropical  land,  where  the  climate  has  a  tendency  to 
be  arid.  And  besides,  the  Cocopas7  ears  are  usually  very  completely 
protected  by  the  dense  mat  of  tarred  hair  which  is  allowed  to  grow 
long  and  hang  loosely  about  the  head,  thus  covering  the  ears  almost 
completely. 

The  number  of  individuals  measured  was  too  few  to  speak  defi- 
nitively, but  it  seems  fairly  safe  to  assume  that  Coeopas  do  not  have 
auditory  acuity  which  is  equal  to  that  of  Whites.  It  is  almost  cer- 
tain that  it  is  not  superior. 

The  Vancouvers  (Nutken  and  Kwaguitl)  Indians.— (For  a  de- 
scription of  these  people,  see  Chapter  II.,  page  8.)  I  was  able  to 
secure  records  of  the  auditory  acuity  of  all  seven  of  these  Indians, 
from  the  southern  portion  of  Alaska,  who  were  present  at  the  Exposi- 
tion. I  shall  present  the  data  relating  to  this  group  in  detail,  as 
shown  in  the  accompanying  table. 

On  the  average,  it  is  seen  that  these  Indians  have  an  acuity  of 
hearing  only  about  one  half  as  great  as  do  the  whites  (see  Table  XV., 
p.  90).  Considering  the  large  amount  of  variation  among  the 
records,  the  averages  for  right  and  left  ears  respectively  do  not 
differ  to  any  significant  extent.  The  records  of  the  two  women  show 
an  acuity  strikingly  poor,  though  the  records  are  probably  not  repre- 


100 


THE   HEARING   OF  PRIMITIVE   PEOPLES 
AUDITORY  ACUITY 


Name 

Age 

40 
27 
21 
28 
35 
30 
64 

Tribe 

Right  Ear 

Left  Ear 

A  =  X10-" 

£  =  XlO-7ergs 

A  =  X10-° 

E  =  X  NT7  ergs 

Bob     . 

Kwaguitl 

Nutken 
« 

Kwaguitl 

Nutken 
« 

<( 

3.3 

14.1 
6.2 
8.1 
18.1 
10.3 
(29.9) 

2.8 
49.0 
9.5 
17.0 
80.0 
28.0 
(2300.0) 

5.0 
18.1 
4.0 
3.3 
15.7 
14.1 
(29.9) 

6.3 

80.0 
4.0 
2.8 
64.0 
49.0 
(2300.0) 

Jasper 

Jack  Curley  
Charley  Newell.. 
Ellen  

Atleo 

Average  

10.01 

31.05 

10.03 

34.3 

sentative  of  the  Vancouver  Indian  women  as  a  whole.  Atleo,  an  old 
man,  made  a  poorer  record  than  the  women,  as  did  also  Jasper,  but 
Jasper  had  experienced  a  hearing  difficulty  at  one  time,  although 
when  the  test  was  made  he  did  not  believe  his  hearing  in  any  way 
defective. 

One  of  the  seven  had  an  acuity  equal  to  that  of  the  median  of 
Whites  with  the  right  ear,  three  with  the  left,  but,  on  the  whole,  the 
hearing  records  of  the  Kwaguitl  and  Nutken  Indians  are  low,  making 
it  plausible  to  believe  that  the  Alaskan  Indians  as  a  class  possess  an 
auditory  sensitivity  decidedly  less  acute  than  do  Americans  and 
Europeans. 

Patagonian  Indians — The  Tehuelche.—  (For  a  description  of  these 
people  see  Chapter  II.,  p.  10.)  I  was  able  to  make  tests  on  four  of 
the  Indians  of  this  tribe  only,  all  being  men.  The  data  relating  to 
their  auditory  acuity,  in  detail,  follow : 

AUDITORY  ACUITY 


Name 

Age 

Bight  Ear 

Left  Ear 

(A=XlO-») 

(E=X10-7  ergs) 

(A=X10-») 

(E-X10-7) 

Cosimero  
Canaio  

24 
35 
55 

18 

7.1 
5.0 

(127.2) 
24.9 

13.0 
6.3 
(4300.0) 
160.0 

7.1 
29.9 
(127.2) 
14.1 

13.0 
230.0 
(4300.0) 
49.0 

Senchel  

BoniFarci... 

Average         12.3X10-9 

59.7X10~7erg8 

17.01X10-9 

97.  3X10-7  ergs 

For  neither  ear;  is  there  a  single  record  of  the  hearing  of  these 
Indians  which  is  as  good  as  the  median  record  for  Whites.  On  the 
average,  their  auditory  acuity  is  less  than  one-half  as  good  as  that 
of  Whites  for  each  ear.  Moreover,  these  were  not  old  men  nor  were 
they  in  any  respect  prematurely  aged.  On  the  contrary,  they  were 
sturdy,  vigorous,  and  in  good  health.  Indeed,  so  far  as  I  was  able 
to  learn,  there  was  no  apparent  physical  reason  why  their  hearing 


RESULTS  101 

should  not  be  good.     We  may  not  assume,  however,  that  a  group  as 
small  as  this  is  representative  of  the  Patagonian  natives. 

Resume  of  the  Hearing  of  Indians.— If,  now,  we  group  the  native 
Indians  together  and  consider  them  as  a  single  group,  we  have  alto- 
gether twenty  records.  (Table  XVII.)  It  is  thus  seen  that  only 
two  of  the  twenty  native  Indians  have  auditory  acuity  records  equal 
to  the  median  for  the  right  ear  of  Whites,  and  three  for  the  left  ear. 
While  even  yet  the  whole  number  measured  is  not  large,  it  certainly 
is  sufficiently  great  to  justify  the  rather  positive  inference  that,  on 
the  whole,  Indians  hear  less  well  than  do  Whites.  Furthermore,  if 
we  compare  this  group  of  native  Indians  with  those  who  have  been 
in  attendance  at  the  U.  S.  Government  Schools,  it  will  be  noted  as 
striking  that  the  more  intelligent  Indians— those  who  have  been  sub- 
jected to  the  influences  of  civilization— have  a  better  auditory  acuity 
than  do  those  who  have  been  closest  to  nature  and  a  natural  life. 
So  far  as  our  American  Indians  of  the  plains  are  concerned,  there-; 
fore,  it  can  not  be  averred  that  their  senses  deteriorate  with  increased 
contact  with  civilization. 

Filipinos.—  (See  Chapter  II.,  page  6,  for  a  description  of  these 
people.)  Of  the  Filipinos,  I  measured  the  hearing  of  137  indi- 
viduals. As  will  be  seen  by  reference  to  Table  IV.,  the  Filipinos 
were  all  men  in  the  prime  of  life,  in  fact,  young  men  in  their  teens 
or  just  beyond  twenty.  A  more  favorable  group  of  individuals  for 
testing  it  would  be  difficult  to  find,  and  especially  is  this  true  when 
we  remember  that  for  the  most  part  they  were  also  rather  decidedly 
above  the  average  of  native  Filipinos  in  intelligence  and  social  cul- 
ture. The  group  had  been  selected  somewhat  on  the  basis  of  hear- 
ing before  reaching  the  United  States.  In  choosing  the  men  for 
army  service  those  men  had  been  rejected  whose  auditory  acuity  was 
discovered  to  be  too  low.  Just  what  was  the  nature  of  the  auditory 
test  I  was  unable  to  learn,  but  from  the  information  which  I  could 
glean  from  the  men  and  officers  in  charge,  and  from  requirements 
in  other  particulars,  made  of  those  enlisted  in  the  Filipino  service, 
I  would  judge  that  nothing  more  was  required  in  the  way  of  hearing 
acuity  than  ability  to  understand  military  directions  spoken  in  an 
ordinary  tone  of  voice. 

The  relative  position  occupied  by  the  Filipinos  as  regards  their 
auditory  acuity  may  be  seen  by  reference  to  the  data  in  tables  XV., 
XVI.,  XVII.  and  XVIII.  (pages  90-92).  In  terms  of  the  average 
result  of  the  group,  for  the  right  ear,  the  condensation  of  a  sound 
wave  (A)  must  equal  24.2  X  10'9  (tf  =  160.0  X  10'7  ergs)  and  for 
the  left  ear  26.6  X  10'9  (#  =  171.0  X  10'7  ergs)  to  excite  an  au- 
ditory sensation  such  as  is  required  to  interpret  the  stimulus  in  the 


102  THE   HEARING   OF  PRIMITIVE   PEOPLES 

hearing  test  herein  employed.  It  may  be  noticed  that  the  figures 
for  Whites  are  5.6  X  10"9  (#  =  7.7  X  10'7  ergs)  and  7.2  X  10'9 
( E  =  12.0  X  10~7  ergs)  for  the  right  and  left  ears  respectively. 
These  are  rather  extraordinary  figures,  in  that  they  indicate  that  on 
the  average  Filipinos  possess  a  sense  of  hearing  which  is  only  about 
one  twentieth  as  keen  as  Whites,  taking  as  a  basis  of  comparison 
the  acuity  of  the  right  ear  of  the  two  groups.  This  means  that 
Filipinos  on  the  average  require  21  times  as  much  energy  to  excite 
an  auditory  sensation  as  do  Whites.  For  the  left  ear  the  sonorous 
energy  required  is  about  14  to  1  in  favor  of  the  Whites.  The  dif- 
ference between  the  two  groups  is  so  marked  that  there  does  not 
appear  the  slightest  chance  of  its  obliteration,  however  large  the 
groups  of  Filipinos  and  Whites  respectively  might  be  made.  To  be 
sure,  the  average  deviations  for  Filipinos  are  large;  but  no  larger, 
proportionately,  than  are  the  corresponding  deviations  for  Whites. 

Applying  statistical  methods  to  the  data,  for  the  two  groups,  to 
ascertain  the  relative  mathematical  certainty  of  a  difference  in  their 
hearing,  it  is  found  that  the  chances  in  favor  of  a  difference  between 
the  groups  are  practically  infinite.  The  chances  are  300  to  1  that 
the  difference  in  condensation  of  a  sound  wave  required  to  excite 
hearing,  between  the  two  peoples  is  at  the  least  15.00  X  10~9,  or 
300  to  1  that  the  hearing  acuity  of  Filipinos  is  only  one  ninth  that 
of  the  Whites  for  both  ears.  Exactly  the  same  differences  appear 
if  we  select  only  the  median  cases— the  50  per  cent,  of  the  cases  dis- 
tributed equally  about  the  median— as  will  appear  by  reference  to 
Table  XVI.  (p.  90).  Referring  now  to  tables  XVII.  and  XVIII., 
it  is  seen  that,  for  the  right  ear,  nine  Filipino  hearing  records  only, 
and  for  the  left  ear  but  six  of  a  total  of  137,  are  as  high  as  the 
median  record  of  Whites. 

When  the  hearing  was  being  tested  at  the  Exposition,  both  Pro- 
fessor Woodworth  and  I  noticed  that  the  Filipino  peoples  were  doing 
very  poorly  indeed.  At  first,  there  was  a  disposition  to  attribute  it 
to  a  defect  in  the  working  of  the  instrument.  But  this  was  found 
to  be  untrue,  since  a  comparison  of  my  own  hearing  record,  which 
always  immediately  followed  that  of  each  Filipino  tested,  showed  the 
testing  device  to  be  working  normally. 

I  am  at  a  loss  to  account  for  this  remarkable  difference  between 
the  auditory  acuity  of  the  Filipinos  and  Whites.  One  point  of 
interest  has  already  been  referred  to  in  connection  with  the  discus- 
sion of  the  upper  limit  of  hearing  of  these  people.  It  was  remarked 
in  that  connection  that  some  of  the  Americans  who  had  resided  in 
the  islands  for  two  or  three  years  had  observed  that  their  own  hear- 
ing was  very  poor  while  in  the  Philippines,  a  fact  which  they  be- 


RESULTS  103 

lieved  to  be  attributable  to  over-dosing  with  quinine,  a  drug  which 
they  found  it  necessary  to  use  freely  to  ward  off  tropical  fevers. 
But,  as  was  then  stated,  Filipinos  are  immune  to  attacks  of  these 
febrile  diseases.  They  use  no  quinine  or  other  drug  with  like  prop- 
erty, so  the  explanation  of  auditory  inferiority  which  takes  into  ac- 
count the  use  of  quinine,  is  unsatisfactory  so  far  as  it  relates  to  the 
natives.  Were  the  relative  inferiority  confined  to  this  one  hearing 
test  alone  it  might  be  interpreted  as  at  least  in  part  due  to  the 
Filipinos'  inability  to  react  to  the  test  from  one  cause  or  another. 
But  a  like  unfavorable  difference,  it  will  be  recalled,  was  found  to 
obtain  with  reference  to  their  upper  limit  of  hearing.  The  inferi- 
ority probably  extends  to  all  phases  of  hearing. 

In  order  to  determine  to  what  extent  the  records  from  this  test 
would  correlate  with  those  for  the  upper  threshold  of  hearing,  I 
worked  out  the  Pearson  coefficient  of  correlation18  for  all  the  Fili- 
pino records,  employing  both  methods — for  relative  position  and  for 
average  difference.  By  the  first  method,  the  coefficient  of  correlation 
between  auditory  acuity  and  the  upper  limit  of  hearing  of  Filipinos 
was  +  0.2907.  By  the  second  method,  the  coefficient  of  cor- 
relation between  the  two  amounted  to  +  0.5408.  The  amount  of 
correlation  is  certainly  fairly  large.  And,  taking  into  consideration 
an  instrumental  error  amounting  to  between  5  and  10  per  cent,  in 
each  series,  the  degree  of  correspondence  is  about  as  great  as  might 
be  looked  for  where  the  measures  are  of  quantities  that  are  as  variable 
in  nature  as  are  those  of  any  sensory  test. 

Looking  at  the  distribution  of  the  records  of  individuals  in  the 
two  tests  respectively  we  discover  that  of  the  25  individuals  who 
ranked  highest  in  auditory  acuity,  18  are  among  the  25  highest  in 
the  upper  limit  test,  and  of  the  25  individuals  who  ranked  lowest  in 
auditory  acuity— i.  e.,  did  most  poorly— 21  are  also  among  the  25 
poorest  in  the  test  for  the  upper  threshold  of  audibility.  The  char- 
acter of  the  coefficient  of  correlation  together  with  the  figures  show- 
ing the  correspondence  in  the  cases  of  the  records  at  the  extremes, 
although  they  indicate  that  some  definite  correlation  exists  between 
hearing  acuity  and  the  limit  of  hearing,  do  not  show  a  point  for 
point  correspondence  such  as  to  justify  one  test  for  both  functions 
in  a  purely  functional  hearing  test.  The  results  furnish  evidence, 
it  seems  to  me,  in  support  of  the  theory  that  in  its  ultimate  analysis, 
pitch  discernment  is  closely  related  to  the  factor  of  intensity. 

The  relation  that  exists  between  auditory  acuity  and  intelligence 

™r='2<vy/nff1<r2  in  which  r  is  the  required  coefficient;  x  and  y  the  devia- 
tions of  an  individual  from  the  averages  of  the  two  series  of  measurements; 
n  the  number  of  individuals;  o^  and  <r2  the  standard  deviations  of  the  two 
series  of  measurements. 


104 


THE   HEARING   OF   PRIMITIVE    PEOPLES 


was  likewise  investigated  to  a  certain  extent.  In  connection  with 
other  tests  and  measures,  we  had  the  people  whom  we  measured  at 
the  Exposition  perform  certain  intelligence  tests,  which  were  more 
or  less  simple  in  character.  Among  the  intelligence  tests  was  a 
simple  ''form  test"  which  we  believed,  from  observation,  to  cor- 
relate roughly  with  intellectual  ability.  The  test  consisted  in  select- 
ing certain  blocks,  cut  into  geometrical  forms,  which  were  arranged 
in  random  order,  and  placing  them  into  holes  of  corresponding  shapes 
which  had  been  cut  into  a  board.  A  record  was  made  (1)  of  the 
time  required  to  perform  the  operation  as  well  as  (2)  of  the  accuracy 
with  which  it  was  done.  Taking  the  time  required  to  perform  this 
test  by  Filipinos  and  their  auditory  acuity,  the  Pearson  coefficient 
of  correlation  was  +  0.238.  While,  therefore,  the  correlation  be- 
tween intellectual  ability,  as  measured  by  this  intelligence  test,  and 
auditory  acuity  is  not  very  considerable,  it  does  show  that  intellectual 
ability  is  a  factor  that  must  be  reckoned  with  in  sensory  measures, 
even  though  the  tests  be  as  simple  in  character  as  were  those  of 
auditory  acuity,  and  especially  is  this  true  in  the  case  of  tests  on 
primitive  peoples. 

I  had  an  opportunity  to  test  the  factor  of  intelligence  as  regards 
its  relation  to  auditory  acuity  a  little  farther,  in  the  case  of  the  Fili- 
pinos. Among  other  Filipinos  tested  for  hearing  were  fourteen 
students,  who  were  in  attendance  at  various  American  universities 
and  colleges.  I  separated  the  hearing  records  of  these  Filipinos 
from  the  others  in  order  to  compare  them  with  those  of  Filipinos  of 
the  more  humble  walks  of  life.  These  student  records  for  the  hear- 
ing of  the  right  and  left  ears,  respectively,  I  will  present  in  full : 


FILIPINO  STUDENTS — AUDITORY  ACUITY — INDIVIDUAL  RECORDS 


Right  Ear 

Left  Ear 

A  =  X  10-9 

^=XlO-7ergs 

A  =  X  10-» 

^=X~7ergs 

1 

2.5 

1.6 

1.9 

0.9 

2 

2.8 

2.0 

2.1 

1.1 

3 

3.0 

2.3 

3.3 

2.8 

4 

2.5 

1.6 

3.3 

2.8 

5 

3.0 

2.3 

3.3 

2.8 

6 

3.3 

2.8 

4.0 

4.0 

7 

3.3 

2.8 

4.0 

4.0 

8 

3.3 

2.8 

4.5 

5.0 

9 

3.6 

3.3 

4.5 

5.0 

10 

3.6 

3.3 

4.5 

5.0 

11 

4.5 

5.0 

4.5 

5.0 

12 

4.5 

5.0 

6.2 

9.5 

13 

15.7 

64.0 

15.7 

64.0 

14 

15.7 

64.0 

36.5 

330.0 

Average  

5.0 

11.6 

6.40 

31.5 

RESULTS 


105 


Of  these  records  of  Filipino  students,  it  will  be  seen  that  all 
except  the  last  two  are  above  the  median  hearing  record  of  Whites, 
in  case  of  both  the  right  and  the  left  ears.  But  it  has  been  ques- 
tioned whether,  after  all,  this  difference  in  hearing  between  the  stu- 
dents and  the  common  native  Filipinos  is  really  a  matter  of  intelli- 
gence at  all  but  rather  due  to  the  fact  that  these  individuals  had 
been  longer  in  the  United  States  and  hence  had  become  somewhat 
more  acclimated  than  had  the  soldiery,  who  came  to  St.  Louis  di- 
rectly from  the  islands.  It  is  difficult  to  conceive,  though,  how  a 
climate  so  different  from  that  in  their  natural  habitat,  in  which  they 
and  their  forefathers  had  lived  for  centuries,  could  be  effective  in 
bettering  a  sensory  quality.  Indeed,  the  argument  would  sound 
more  plausible  were  we  to  reason  conversely  that  their  hearing  be- 
come poorer  in  the  United  States  because  of  their  longer  sojourn  here. 

Ainu.—  (For  a  more  complete  description  of  these  people,  see 
Chapter  II.)  The  composition  of  the  Ainu  group  was  not  the  most 
favorable  for  an  auditory  acuity  test.  In  addition  to  the  too  great 
variation  in  ages  among  the  peoples,  it  appears  that  to  some  extent 
the  different  individuals  of  the  group  were  interrelated.  In  testing 
a  related  group  such  as  this,  consequently,  there  is  some  possibility 
that  what  is  really  being  measured  is  a  family  characteristic  rather 
than  a  racial  trait.  I  shall  present  the  records,  however,  as  I  se- 
cured them: 

AINU — AUDITORY  ACUITY 


"N~n.ni  A 

Ei 

ght  Ear 

L 

eft  Ear 

A  =  X  10~» 

£  =  X  10-'  ergs 

A  =  X  10-» 

£=X  10-'  ergs 

Yazo  Osawa                 

?S 

5  5 

7  5 

8.1 

17.0 

Kutorj*e  Hiramura  

38 

21  1 

1100 

25.0 

160.0 

Goro  Bete              

4.0 

4.0 

6.2 

9.5 

Sangea  Hiramura  

56 

4.5 

5.0 

11.9 

35.0 

Kin  Hiramura  (Daughter  of 
San  irea)  

6 

25.0 

160.0 

11.9 

35.0 

Shrutatek  Hiramura  (Wife  of 
Kutorffe)  

33 

11.9 

35.0 

18.1 

80.0 

Ume  Osawa  (Wife  of  Yazo)  ... 

19 
53 

36.5 
36.5 

330.0 
330.0 

11.9 
43.4 

35.0 
450.0 

Average  

18.12 

122.7 

17.06 

102.7 

In  making  up  the  averages  for  this  group,  I  included  the  records 
of  all  the  individuals  examined,  in  spite  of  the  fact  that  they  pre- 
sented wide  variations.  In  case  of  a  doubtful  record  in  making  up 
the  averages  of  larger  groups,  such  as  the  Whites  or  the  Filipinos, 
I  observed  the  rule  laid  down  by  Professor  Cattell  of  rejecting  the 
record  of  any  individual  if  its  divergence  from  the  average  exceeded 
three  times  the  average  deviation.  Such  a  record  is  more  likely  to 


106  THE   HEARING   OF  PRIMITIVE   PEOPLES 

be  an  instrumental  error  or  to  be  a  case  of  pathological  functioning 
than  a  question  of  simple  deviation  from  the  average.  Such  a  pro- 
cedure in  the  case  of  the  records  of  the  Ainus,  however,  would  be 
difficult  to  follow. 

Of  the  eight  records  of  hearing  for  the  right  ear,  five  were  very 
poor  and  only  three  fair  in  comparison  with  those  of  Whites,  while 
for  the  left  ear,  seven  of  the  eight  are  relatively  poor,  though  for 
this  ear  the  average  shows  slightly  higher  than  that  of  the  right. 
None  of  the  Ainu  people,  in  case  of  either  ear,  stand  as  high  as  the 
median  records  for  Whites,  for  corresponding  ears.  While  it  is  not 
permissible  to  become  dogmatic  from  so  small  a  sampling,  it  seems 
probable  enough  that  the  average  of  a  large  group  of  Ainu  people 
would  show  about  the  same  relative  inferiority  with  respect  to  au- 
ditory acuity  as  was  discovered  among  the  few  examined.  At  the 
time  of  making  the  examinations,  and  again  some  months  later,  I 
inquired  carefully  of  each  person  whether  he  or  she  had  ever  observed 
that  his  hearing  was  defective,  but  the  replies  were  invariably  in  the 
negative.  There  is  no  way  in  which  the  question  can  be  investigated 
other  than  by  the  method  of  observation  and  selection,  but  I  am  con- 
vinced that  the  inferiority  of  the  Ainu  in  respect  to  this  sense  is  due 
in  no  small  part  to  their  sluggishness  in  reacting  to  impressions.  So 
sluggish  and  unresponsive  are  they,  that  a  stimulus  of  more  than 
ordinary  intensity  is  required  to  arouse  them,  and  it  seems  not  un- 
natural that  weak  auditory  stimuli  should  fail  to  break  over  the 
threshold  of  consciousness.  Confirmatory  of  this  opinion  is  the  fact 
that  of  the  eight  individuals  tested,  the  three  who  were  the  most 
intelligent  and  alert  of  the  group  were  likewise  the  three  who  pos- 
sessed the  best  records  of  hearing  acuity. 

No  effort  was  made  to  differentiate  the  sexes  in  the  tests,  though 
it  will  be  seen  from  the  data  that  the  average  acuity  of  the  women 
is  considerably  less  than  that  of  the  men.  The  record  of  Kin  was 
high  also,  and  perhaps  should  have  been  omitted  in  making  up  the 
average,  but  she  seemed  to  understand  the  procedure  and  to  react  as 
intelligently  to  the  questions  put  to  her  as  the  average  of  her  people, 
and  for  this  reason  her  record  was  included  with  the  others. 

Pigmies.— (For  a  description  of  these  people  see  Chapter  II., 
page  9.)  It  would,  perhaps,  be  better  to  consider  this  group  as  one 
of  native  African  Negroes,  rather  than  of  a  particularly  primitive  or 
aboriginal  race.  Some  of  the  number,  at  least,  were  not  Pigmy  at 
all :  they  belonged  to  a  type  of  large  red  negro  found  in  the  central 
Congo  district.  Yet  even  as  regards  Negroes  who  have  been  little 
influenced  by  the  habits  and  arts  of  civilization,  they  will  give 


RESULTS 


107 


instructive  information.  I  shall  give  the  data  relative  to  their  ages 
and  tribal  connections  as  it  was  given  us  together  with  the  hearing 
records  which  I  was  able  to  make,  in  the  following  table : 


PIGMIES — AUDITORY  ACUITY 


Name 

Age 

Tribe 

Right  Ear 

Left  Ear 

A  =  X  Ifr-9 

E=  X  10-T  ergs 

A=XN>-» 

E=  X  10-7  ergs 

Shamba  

30 
16 
13 
15 
17 

Batwa 

u 

« 

Batsuba 
« 

6.2 
11.9 
18.1 
9.1 
6.2 

9.5 
35.0 
80.0 
21.0 
9.5 

6.2 
9.1 
7.1 
9.1 
6.2 

9.5 
21.0 
13.0 
21.0 
9,5 

Malinera 

Bushaba      

Latuna  . 

Average  

10.31 
3.55 

31.0 
20.8 

7.54 
1.24 

14.8 
7.6 

In  contrast  with  the  records  of  the  Ainu  just  considered,  it  is 
seen  that  the  Pigmies  present  a  rather  homogeneous  group  so  far  as 
auditory  acuity  is  concerned.  For  both  ears  the  average  deviations 
are  small.  This  probably  is  due,  at  least  in  part,  to  the  fact  that 
the  individuals  were  about  of  an  age,  and  differed  little  tempera- 
mentally from  one  another.  It  will  be  remembered  that  for  the 
upper  threshold  of  hearing  the  Pigmy  records  were  all  high,  and  if 
the  same  relative  distribution  were  to  follow,  were  the  number 
increased  indefinitely,  Pigmies  would  possess  an  upper  threshold  for 
hearing  superior  to  that  of  any  other  race,  not  being  inferior  to  even 
Whites  in  this  respect.  An  equal  degree  of  superiority  was  not 
attained  by  Pigmies  in  auditory  acuity,  although  for  the  left'  ear 
(see  Table  XV.)  the  average  acuity  of  Pigmies  is  slightly  higher 
than  that  of  the  same  ear  for  Indians  who  next  approach  Whites 
in  keenness  of  hearing ;  the  record  for  the  right  ear  falls  below  that 
of  both  Whites  and  Indians.  Little  significance  perhaps  may  be 
attached  to  an  average  measure,  where  the  numbers  measured  are  so 
few,  but  the  character  of  the  distribution  of  the  group  seems  to 
indicate  a  decided  inferiority  for  the  hearing  of  the  Pigmies  as  com- 
pared with  those  of  both  Whites  and  Indians.  The  curve  of  their 
hearing  falls  perceptibly  lower,  the  average  being  relatively  higher 
owing  possibly  to  the  fact  that  none  of  the  Pigmies  possessed  any- 
thing in  the  way  of  an  organic  hearing  defect,  which  might  tend  to 
lower  the  standing  of  the  group.  An  explanation  of  the  differences 
found  between  the  comparative  records  of  Whites  and  Pigmies  in 
the  upper  threshold  of  hearing  and  for  simple  acuity  respectively 
might  be  given  on  an  intellectual  basis.  In  the  test  for  the  upper 


108  THE   HEARING   OF  PRIMITIVE    PEOPLES 

threshold  of  hearing,  the  stimuli  are  of  longer  duration.  More- 
over, they  require  no  interpretation,  and  consequently  the  feeling  of 
hearing  the  sound,  which  really  has  only  a  subthreshold  value,  may 
be  more  easily  accomplished,  than  the  actual  interpretation,  which 
the  counting  of  the  stimuli,  implied  in  the  simple  acuity  test,  neces- 
sitates. I  put  this  forth  as  suggestive  only. 


CHAPTER   XI 

SUMMARY  AND  CONCLUSION 

IT  is  very  difficult  to  compare  the  foregoing  results  with  those  of 
Myers  in  the  same  field,  by  reason  of  the  differences  in  the  method 
employed  in  collecting  data.  In  the  classic  work  of  Myers,  on 
Papuan  hearing,  several  different  devices  for  testing  the  hearing  of 
the  primitives  were  employed.1  And  to  such  an  extent  were  these 
different  measures  therefore  confused  that  it  was  necessary  for 
Myers  to  report  all  the  data  he  collected  in  terms  of  a  personal 
fraction  in  which  the  hearing  of  one  of  the  members  who  made 
up  the  expedition  was  the  denominator,  while  that  of  the  subject 
constituted  the  numerator.  Of  the  35  Islanders  who  were  examined 
for  auditory  acuity  by  Myers,  the  hearing  of  seventeen  only  was 
reported  and  of  these  twelve  were  children,  five  only  being  adults. 
Of  the  children  five  could  hear  as  far  as  Myers ;  seven  were  clearly 
inferior ;  and  of  the  adults  examined,  all  possessed  a  very  low  acuity. 
Although  consequently  I  can  speak  only  in  general  terms,  Myers's 
conclusions  do  not  appear  to  differ  essentially  from  my  own  in  this, 
that  they  point  out  clearly  the  obvious  superiority  of  Whites  over 
primitive  races  in  the  keenness  of  their  hearing  sense. 

With  my  smaller  groups,  as  has  been  repeatedly  stated,  the  num- 
ber examined  is  insufficient  to  do  more  than  indicate  a  general 
tendency  of  the  group  within  the  region  of  a  large  probable  error. 
Especially  is  this  true  of  such  peoples  as  the  Vancouvers,  the 
Pigmies,  and  the  Cocopas,  where  it  is  difficult  to  predict  with  any 
degree  of  probability  the  character  that  the  hearing  curve  of  the 
peoples  as  a  whole  might  assume,  inasmuch  as  the  records  are  so 
scattered — some  being  fairly  high;  others  extremely  poor.  But  in 
the  case  of  such  groups  as  the  Indians,  Filipinos  and  Whites,  the 
number  of  measurements  is  sufficient  to  give  at  least  the  general 
character  of  a  complete  distribution  of  the  race  as  a  whole. 

Taking  the  results  of  all  the  groups  examined  for  what  they  are 
worth  their  standings  respectively  are  as  follows,  as  regards  the 
acuity  of  the  right  ear : 

Whites ;  Cocopas ;  Indians  from  the  School ;  Pigmies ;  Patagonian 
Indians;  Vancouver  Indians;  Ainu,  and  lastly,  Filipinos. 

For  the  left  ear,  the  order  is  slightly  changed,  Whites  and 

1See  Report  of  the  Cambridge  Anthropological  Expedition  to  Torres 
Straits,  Vol.  II. 

109 


110 


THE   HEARING   OF  PRIMITIVE   PEOPLES 


Filipinos,  however,  still  retaining  the  positions  at  the  two  extremes ; 
the  order  from  the  most  acute  people  to  the  least  acute  being : 

Whites;  Pigmies;  Indians  from  the  School;  Cocopas,  Vancouver 
Indians;  Ainu;  Patagonians  and  Filipinos. 


^\ 


^ 


R 

i 


r 


I 
i 

1. 

i! 
II 


i 


<* 


1 


1! 


/     •• 


•£*     « 
l/f    " 

|/7  * 

l/4*"« 

l/^. 


/»„ 


9 


/  -* 

o  •• 


It  will  be  observed  that  the  relative  positions  of  the  three  most 
numerous  groups,  namely  Whites,  Indians  from  the  School,  and 


SUMMARY   AND   CONCLUSION  HI 

Filipinos  remain  unchanged.  Indeed,  they  retain  in  respect  to  each 
other  about  the  same  relative  position  for  both  the  right  and  left 
ears,  and  also,  when  the  basis  of  comparison  is  that  of  absolute  units 
of  hearing,  instead  of  relative  position.  To  summarize  the  various 
comparisons  which  have  been  made  in  connection  with  the  data 
relating  to  the  several  groups,  we  may  show  the  following  ratios 
indicating  the  relative  keenness  of  the  hearing  sense  of  each  group 
as  compared  with  that  of  Whites : 

Right  Ear  Left  Ear 

Whites — Cocopas  Ratio     7  to  5  Ratio     9  to  7 

Whites — Indians    (School)    

Whites — Pigmies   

Whites — Patagonians   

Whites — Vancouver   Indians 

Whites — Ainus 

Whites — Filipinos   


9  to  5  8.5  to  7 

10.5  to  5  "        7.5  to  7 

12  to  5  "  17.5  to  7 

10  to  5  "  10  to  7 

18  to  5  "  17  to  7 

24  to  5  "  26.5  to  7 


Preyer,  Fechner,2  Bezold  and  others  have  observed  that  in  hear- 
ing tests,  the  left  ear  in  general  is  more  acute  than  the  right.  Miss 
Nelson,3  on  the  contrary,  found  that  in  both  men  and  women  the 
right  ear  was  the  better.  The  left  ear,  it  will  be  remembered,  was 
found  to  be  superior  with  respect  to  the  tests  for  the  upper  threshold 
of  hearing.  In  case  of  the  ears  of  each  of  the  larger  groups,  my  own 
experiments  in  general  confirm  the  observations  of  Miss  Nelson  as 
opposed  to  those  of  Fechner  and  Bezold.  The  acuity  of  the  left  ear 
not  only  of  the  three  larger  groups  but  in  three  of  the  five  smaller 
ones,  is  clearly  inferior  to  the  right,  the  Pigmies  and  Ainus  alone 
being  exceptions.  When  making  the  measurements  of  the  upper 
threshold,  it  will  be  recalled  that  it  was  stated  that  almost  invariably 
the  right  ear  was  first  tested.  In  consequence,  I  believed  the 
superior  upper  limit  of  the  left  ear  to  be  due  to  the  effect  of  practise 
in  hearing  shrill  tones.  But  this  explanation  will  not  apply  to  the 
case  of  the  acuity  test.  Instead  of  testing  invariably  one  particular 
ear  first,  the  process  was  alternated— the  right  and  left  ears  alter- 
nately being  first  tested  in  successive  subjects.  Practise  effects 
could  not,  therefore,  have  been  operative  in  causing  the  average  for 
acuity  of  one  ear  to  be  higher  than  the  other.  It  is,  indeed,  more 
probable  that  the  causal  factor  is  organic  rather  than  psychological. 

The  one  fact  standing  out  most  prominently  as  a  result  of  these 
measurements  is  the  clearly  evident  superiority  of  Whites  over  all 
other  races,  both  in  the  keenness  and  in  the  range  of  the  hearing 
sense.  The  evidence  is  so  clear  and  striking  as  to  silence  effectually 
the  contention  that  the  hearing  function,  inasmuch  as  it  is  of  rela- 

2  Poggendorfs  Annal.   (4th  series)   3:  500. 
'Psych.  Rev.   (suppl.)    12:  280.    1905. 


112  TEE   HEARING   OF  PRIMITIVE    PEOPLES 

lively  less  utility  in  the  pursuits  attending  modern  social  conditions 
than  those  surrounding  the  life  of  the  savage,  has  deteriorated  and 
is  degenerating.  On  the  contrary,  they  are  more  nearly  in  keeping 
with  the  advanced  positions  taken  by  modern  dynamic  psychology, 
to  the  effect  that  not  only  the  intellectual  but  sensory  possibilities 
are  to  be  stated  in  terms  of  the  variety  of  motor  response  of  which 
the  individual  is  capable.  Other  things  being  equal  those  individuals 
or  races  possessing  the  greatest  complexity  and  variety  of  reactions 
to  elements  in  their  respective  environments  likewise  will  be  gifted 
with  keener  and  more  acute  sensory  mechanisms. 

If  all  discrimination  of  data  coming  to  the  senses  must  finally 
be  stated  in  motor  terms,  as  most  psychologists  would  have  us  think, 
then  those  peoples  whose  social  activities  call  for  the  greatest  com- 
plexity of  response  will,  of  necessity,  possess  keener  senses  along 
those  lines  in  which  the  social  media  call  for  closer  discrimination. 
This  motor  aspect  of  a  sensory  function  also  serves,  to  a  certain 
extent,  to  explain  a  rather  startling  auditory  inferiority  on  the  part 
of  some  of  the  natives  of  tropical  lands.  In  these  regions  of  warmth, 
where  lack  of  thrift  and  indolence  are  fostered  by  nature's  bounty, 
in  its  luxuriance  and  plenty  in  the  way  of  food,  in  its  relative  im- 
munity from  exigencies  calling  for  protection  and  shelter,  adaptive 
activities  are  found  at  their  lowest  ebb.  Contrast  these  conditions 
with  those  of  higher  latitudes,  in  which  the  individual  is  in  constant 
strife  to  keep  himself  in  harmony  with  his  surroundings.  And  the 
ear  plays  no  insignificant  role  in  this  endless  round  of  readjustment. 
Roughly,  and  in  general,  the  data  on  hearing  were  found  to  correlate 
with  motor  versatility  as  regards  the  different  races. 

^Then  again  the  more  involved  a  test,  the  more  probable  is  it  that 
differences  in  the  degree  of  intelligence  of  the  subjects  tested  will  be 
effective  in  modifying  in  an  unfavorable  direction  the  performance 
of  the  less  gifted  group.  It  has  already  been  indicated  that  the  test 
for  auditory  acuity  which  I  employed  was  more  than  a  simple  sen- 
sory test,  inasmuch  as  it  required  an  interpretation  of  the  stimuli 
presented  to  the  ear,  and  for  this  reason  it  was  believed  that  some 
of  the  differences  between  the  acuity  of  the  several  peoples  tested 
might  be  attributable  to  the  obvious  fact  that  striking  differences  in 
mental  alertness  obtained  among  the  different  races.  But  to  what 
extent  the  mental  factor  was  responsible  for  the  degree  of  auditory 
inferiority  in  such  a  race  as  the  Filipinos,  it  is  impossible  to  tell  with 
any  degree  of  certainty  from  the  data  at  hand. 

Only  two  factors  have  been  indicated  to  account  for  differences 
in  auditory  acuity  found  among  primitive  races,  and  between  primi- 
tive races  and  Whites.  That  there  are  many  others,  some  perhaps 


SUMMARY   AND   CONCLUSION  H3 

more  significant  and  vital  than  those  pointed  out,  the  writer  only  too 
well  appreciates.  But  the  field  is  new.  And  indeed  the  conditions 
surrounding  the  taking  of  the  measurements  herein  reported  were 
not  as  favorable  for  making  an  intensive  study  of  the  factors  enter- 
ing into  hearing  as  the  importance  of  the  problem  warrants.  Still 
this  is  not  the  phase  of  the  study  that  I  care  to  unduly  emphasize. 
As  significant  as  the  problem  of  racial  differences  in  hearing  is  for 
genetic  psychology,  and  the  writer  feels  this  importance  keenly,  it 
was  to  the  method  employed  in  testing  hearing,  particularly,  that  it 
was  desired  to  call  attention.  Psychology  as  a  science  has  advanced 
to  that  point  where  quantitatively  exact  methods  of  research  ought 
to  be  emphasized,  as  well  for  evaluating  functions  as  for  equating 
differences  between  individuals  or  among  races.  Such  methods  too 
are  demanded  as  are  possible  of  reinstatement,  and  offer  data  in  a 
nomenclature  more  specific  and  determinative  than  normatively  es- 
tablished units  of  measurement  can  give.  If  consequently  the  meth- 
ods that  have  been  used  to  obtain  the  results  herein  presented  succeed 
in  accentuating  the  need  for  more  exact  objective  methods  of  research 
in  experimental  psychology,  the  writer's  purpose  will  have  been  at- 
tained as  effectually  as  by  the  recognition  of  the  light  that  has  been 
thrown  on  the  problem  of  the  hearing  of  the  inferior  races. 


VITA 

Born  at  Streator,  111.,  March  28,  1874;  college  preparatory 
education,  Indiana  Normal  School,  Valparaiso;  entered  Junior 
Class,  University  of  Nebraska,  1901;  A.  B.  Nebraska,  1903.  En- 
gaged as  principal  of  public  schools  1896-99;  Superintendent, 
Dwight,  111.,  City  Schools,  1899-1901 ;  University  Assistant  in  Edu- 
cation, Nebraska,  1902-03.  Fellow,  1903 ;  Assistant  in  Psychology, 
Columbia  University,  1903-05 ;  Assistant  Superintendent  sections  of 
Anthropometry  and  Psychometry,  Louisiana  Purchase  Exposition, 
1904 ;  Assistant  Director,  Department  of  Child  Study  and  Pedagogic 
Investigation,  Chicago  Public  Schools,  1905 ;  Member  Ameri- 
can Association  for  the  Advancement  of  Science,  and  American 
Psychological  Association. 

Previous  publications:  "Investigations  Concerning  Deaf  Chil- 
dren" (in  collaboration  with  D.  P.  MacMallan,  Ph.D.),  Report  of 
Child  Study  Department,  Chicago,  1906,  pp.  86.  "Mental  and 
Physical  Status  of  Truants,"  Report  of  the  Chicago  Parental 
School,  1906,  pp.  9-24.  "Grades  of  Mentality  Among  Public 
School  Children,"  Proc.  Illinois  State  Teachers'  Assn.,  1905,  pp. 
149-157. 


ry  Obrair j 

UNIVERSITY  OF  CALIFORNIA  LIBRARY 
BERKELEY 

Return  to  desk  from  which  borrowed. 
This  book  is  DUE  on  the  last  date  stamped  below. 


29 
NOV  18  1952 

JUN  U 1970     3 

JUN  26  1971 

JUN  1 1  1971     3 


LD  21-100m-ll,'49(B7146sl6)476 


207775 


QP461 
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BIOLOGY 
LIBRARY 

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